Data on the prevalence of sexually transmitted diseases in the United Arab Emirates (UAE) is lacking and scarce. This study was carried out to determine the prevalence of both Treponema pallidum (causative agent of syphilis) and HIV infections among expatriates in Sharjah, UAE. The study group (N = 20,670) included expatriate workers of both sexes undergoing mandatory pre-employment testing between May and June 2014. Detection of specific antibodies to Treponema pallidum and HIV antigens and antibodies was conducted using commercially available kits. Of the 20,670 samples screened for syphilis, one hundred and five (0.51%) tested positive. Expatriates from India (30.5%), Pakistan (25.7%), and Bangladesh (15.2%) showed the highest infection rate with T. pallidum. Moreover, three age groups were most affected with syphilis and a significant correlation was noted between age and T. pallidum infections (x2 = 76.23; p = 0.001). Furthermore, an association was also observed between gender and infection with T. pallidum (x2 = 3.37; p = 0.04). Of the 20,670 samples screened for HIV, three samples (0.014%) tested positive for HIV antibodies and antigen. The results were consequently confirmed by western blot assay. The prevalence of infection with T. pallidum and HIV was determined for the first time among expatriates in Sharjah providing policymakers with data which could be used to develop appropriate prevention and control strategies.