Mother
The mother is entrusted with the care of the child both before and after the Brit. She begins the ceremony by handing the baby to the godmother, thus indicating her consent for the Brit to take place.

Father
Since Abraham is commanded by the Torah to ritually circumcise his son, the obligation to fulfill this Mitzvah lies with the father. Rambam teaches that unlike other Mitzvot, the obligation continues indefinitely until it is accomplished. Therefore, if the father is unable or unwilling, the task falls to the mother, then to the Bet Din, rabbinic court of the community and finally to every member of the Jewish people.

The parents stand next to the Mohel and verbally designate him to act on their behalf. In doing so, and throughout the ceremony, they must have Kavanah, the proper intent, inasmuch as they are participating in the fulfillment of God's commandment.

Kvatterin/Kvatter
The godmother and godfather are a woman and a man, often a married couple seeking to have a child, who will bring the baby into to the room where the Brit takes place and return him to the mother thereafter. There are no legal or traditional responsibilities inherent in this honor. However, in Jewish folklore godparents are responsible for providing the child's religious education if the parents are unable to do so. In some families, the baby is cradled by many people, each bringing him closer to the milieu where the Brit will occur. Aunts, uncles and sometimes grandmothers are chosen. Parents who want to be inclusive often honor all their siblings or others in this way.

Sandak
The word “Sandak” most likely derives from the Greek “Suntekos,” “companion of the child” or “Sundikos,” “patron of the child.” This is one of the highest honors at the Brit, a role equated with that of the high priest who offered the daily incense on the Temple's inner altar. The Sandak holds the child during the actual circumcision. He should be a God-fearing, righteous person who bridges the generations. This honor is often given to one of the grandfathers of the child. If there is more than one grandfather, a special honor called “Amidah Lebrachot” can be added. It is said that if a Sandak or Amidah Lebrachot is a saintly person, who can, with the help of God, instill a strong Jewish spirit in the child.

Amidah Lebrachot
The person (usually the other grandfather) who holds the baby during the naming aspect of the ceremony

Participants-Eliyahu Hanavi
After the death of King Solomon, the Jewish kingdom was divided. Those living in the Kingdom of Ephraim, in Samaria, abandoned the practice of Brit Milah. Elijah, a prophet of the times, cried out to God, "...for the children of Israel have forsaken Your covenant." (I Kings 19:10) Elijah swore that he would prevent rain or dew from falling. God upheld this promise and told Elijah that because of his passionate championship of the Mitzvah of Milah he would have the privilege of attending every Brit that Jews would perform throughout the centuries. For this reason, a chair is set aside in honor of Elijah the Prophet, who is referred to in the ceremony as "the angel of the covenant." The Sandak stands to the left of the chair following the Talmudic dictate that a student walks on his teacher's left. Often a godparent or one of those assembled is honored by briefly placing the infant on the Throne of Elijah so the prophet can bless the child. It is customary to decorate the chair with beautiful sheets or pillows.

Participants-Others
A Minyan is preferred, but is not mandatory. Because Elijah is an honored guest, it is fitting to recognize his presence with a Minyan. All stand throughout the ceremony. This derives from the verse, "...and the entire nation stood at the covenant" (II Kings 23:3), when King Josiah renewed Israel's commitment to the Torah.

Participants-Mohel
The Mohel should be a competent “Shomer Mitzvot,” “Torah observant Jew” of the highest character. He should be thoroughly knowledgeable regarding current medical practice as well as Halacha, Jewish law. It is preferable that the Mohel be a person who impresses the sign of the covenant upon the child should himself be a member of the covenant.

A Mohel is trained by the preceptor method, apprenticing himself to a master teacher. There is normally no prescribed duration for the course of study. Each candidate advances at his own pace, absorbing instruction in medical science (anatomy, hematology, physiology and pathology); techniques of sterilization; pre and post operative procedures and the laws and customs included in Yoreh De-ah, Talmudic literature, codes, responsa and at least one Milah textbook such as Sefer HaBrit, Brit Avot or Zocher HaBrit. When the teacher deems the training complete, he recommends the candidate to the local certifying board. Such a board may consist of Rabbis, Mohalim and Physicians who evaluate the candidate for his knowledge, reverence and expertise.

Brit Milah is a sacred religious ceremony, not merely a medical procedure. Therefore, a physician does not automatically qualify to be a Mohel. In fact, some rabbinic authorities have objected to doctors, even religious ones, serving as Mohalim in order to avoid a trend toward using medical practitioners who do not meet the standards of ritual observance.

The Mohel also must have the proper intention, Kavanah, during the Brit. It is said that he should keep in mind the thought that in carrying out this ritual it is as if he were observing all of the 613 commandments. (Zikhron Brith L'Rishonim)