Swingers are couples practicing consensual extradyadic heterosexual relations. This subculture is defined by venues and online communities. This study aimed to assess swingers' lifestyle, sexual health, and history of testing for sexually transmitted infections (STIs) and to review risk factors for sexual risk behavior and STI transmission. An online survey was distributed through venues, chat websites, and dating websites. Most of 480 swingers starting the survey completed it (n = 392, 81.6%). Women (n = 146) reported more frequent swinging (p = 0.013), same-sex contacts (p < 0.001), and more sex under influence of alcohol (p < 0.001). Men (n = 334) reported more anal sex (p = 0.002) and condomless vaginal sex (p = 0.004). Of respondents tested, 25.7% ever received an STI diagnosis. Using logistical regression, being male, older, single, and party drug use were associated with sexual risk behavior (p = 0.009). Higher frequency of swinging was associated with an STI diagnosis (p = 0.036). Swingers were sexually active, reported factors associated with sexual risk behavior, and were more diagnosed with an STI compared to the general population. Many swingers were tested for STIs. Nonetheless, implementation of tailored testing strategies should be considered given their elevated risk for STI acquisition.