A clinic-based intervention to incorporate syphilis testing with routine HIV bloodwork among HIV-positive men who have sex with men (MSM) attending 4 hospital-based HIV clinics in Toronto and Ottawa will be conducted. The objectives are to determine to what degree the intervention: (1) increases the detection rate of untreated syphilis; (2) increases the proportion of men who undergo syphilis testing at least annually (increased screening coverage); (3) reduces the interval between syphilis tests (increased screening frequency); and (4) reaches men at highest risk according to sexual behaviours. The main hypotheses are that the intervention will increase screening coverage to a minimum of 85% of men undergoing syphilis testing annually, increase screening frequency to a median of 3 tests per person per year, and increase the case detection rate by 75% or more.