BACKGROUND: HIV testing is the first point of HIV treatment entry for HIV-infected individuals and an avenue to engage persons at risk in prevention. In China, where the prevalence of HIV among men who have sex with men (MSM) has been rising over the last decade, uptake of HIV testing has been low. METHODS: We examined changes in HIV testing in the preceding 12 months through two cross-sectional surveys conducted among MSM in Nanjing, Jiangsu province, China in 2008 and 2012. Respondent-driven sampling (RDS) was used to recruit participants. Questionnaire interviews and venous blood were collected to measure HIV testing, risk behaviors, and prevalence of HIV, syphilis, and HSV-2. RESULTS: A total of 430 and 589 MSM were surveyed in 2008 and 2012, respectively, with comparable samples in each round with respect to demographic characteristics. HIV testing in the past 12 months increased significantly from 20.1% (95% CI 13.3-26.8) in 2008 to 46.0% (95% CI 39.3-51.4, p < 0.001) in 2012. HIV prevalence was stable, at 6.6% (95% CI 2.5-11.3) in 2008 and 10.1% (95% CI 6.6-13.9, p = 0.240) in 2012, as was syphilis (14.3% in 2008 vs. 9.9% in 2012, p = 0.240). HSV-2 prevalence (18.6% in 2008 vs. 10.2% in 2012, p = 0.040) and self-reported STI in the last year (24.3% in 2008 vs. 14.3% in 2012, p = 0.020) significantly decreased. Changes in reported sexual behaviors were mixed and the profiles of who did and did not test varied between 2008 and 2012. CONCLUSIONS: HIV testing uptake more than doubled among MSM in Nanjing from 2008 to 2012 -a period of massive promotion and scale up of testing programs for MSM. However, additional efforts are still needed to further increase the proportion of men being not only tested but also undergoing repeat testing if they engage in continued risk taking behavior.