Background: Approximately 30% of people living with HIV worldwide are estimated to be unaware of their infection. HIV self-testing (HIVST) is a strategy recommended by the World Health Organization to increase access to and uptake of testing among key populations who are at high risk for HIV infection. Objective: This study aimed to describe the development and feasibility of a free, anonymous, internet-based HIVST strategy designed for men who have sex with men in Curitiba, Brazil (electronic testing [e-testing]). Methods: The project was developed under the scope of the “A Hora é Agora” (The Time is Now) program. Individuals aiming to request an HIVST package (two tests each) answered an anonymous 5-minute questionnaire regarding inclusion criteria and sexual risk behavior. Eligible individuals could receive one package every 6 months for free. Website analytics, response to online questionnaires, package distribution, and return of test results were monitored via a platform-integrated system. Results: Between February 2015 and January 2016, the website documented 17,786 unique visitors and 3218 completed online questionnaires. Most individuals self-reported being white (77.0%), young (median age: 25 years, interquartile range: 22-31 years), educated (87.3% completed secondary education or more), and previously tested for HIV (62.5%). Overall, 2526 HIVST packages were delivered; of those, 542 (21.4%) reported a result online or by mail (23 reactive and 11 invalid). During the study period, 37 individuals who reported using e-testing visited the prespecified health facility for confirmatory testing (30 positive, 7 negative). Conclusions: E-testing proved highly feasible and acceptable in this study, thus supporting scale-up to additional centers for men who have sex with men in Brazil.