While Jewish ritual circumcision continues to be a controversial issue in Europe and the US, metzitzah b’peh, the addendum to brit milah, which requires the mohel (ritual peritomist) to orally suck blood from the wound immediately following the excision of the foreskin, remains a divisive topic. While medical historians have studied European outbreaks of infectious disease following metzitzah b’peh, no one has assessed the response of the nineteenth century New York Jewry. This paper analyses how this nascent community responded to the thorough report by the New York Board of Health following an alleged and discredited outbreak of syphilis attributed to metzitzah b’peh in 1873, especially in the context of nineteenth century immigration, popular perception of syphilis and American medicine.