BACKGROUND: Despite national progress in syphilis control, increases in rates have recently occurred, and syphilis is still an endemic problem in the southern United States. An outbreak of infectious syphilis among Hispanics was identified in Decatur, Alabama. GOAL: An investigation was initiated to describe the outbreak and to assist with prevention activities. STUDY DESIGN: We reviewed case interview records and syphilis surveillance data. The Morgan County Health Department (MCHD) performed voluntary door-to-door syphilis screening in neighborhoods where a large number of cases had been identified. During screening activities, sociodemographic and behavioral data were collected. RESULTS: From June 2000 to February 2001, 49 cases of syphilis were reported; 26 (53%) were primary or secondary, 17 (35%) were early latent, and 6 (12%) late latent. Of the early syphilis cases, 70% were male and half were Hispanic; 93% of cases were linked to commercial sex and 70% of female cases reported crack cocaine use. During the screening, 172 individuals completed a questionnaire; 70% of participants were male, 83% were Hispanic, 17% of Hispanic participants spoke English, 21% reported sex with a commercial sex worker, and 8 (5%) had positive syphilis serology. Among men, factors associated with commercial sex were not having a regular partner (odds ratio [OR], 3.9; confidence interval [CI], 1.1-14.3), not living with a family member in the United States (OR, 4.5; CI, 1.6-12.8), and having visited their country of origin since arrival to the United States (OR, 9.2; CI, 2.3-36.5). CONCLUSIONS: Factors contributing to this outbreak were crack cocaine use and increased prostitution in close proximity to the Hispanic community. At present, there are an increasing number of Hispanic immigrants in the United States, the majority of whom do not speak English. To prevent similar outbreaks in the future, public health officials need to be aware of the health and health education needs of these populations.