Men who have sex with men (MSM) are disproportionally affected by the HIV epidemic. Self-efficacy is an important individual psychosocial factor associated with access to and use of health and HIV-related services. We estimated HIV testing prevalence and examined the relationship between HIV testing self-efficacy and self-reported HIV testing behavior among young MSM (YMSM) in Myanmar. We enrolled 585 MSM aged 18–24 years from six urban areas using respondent-driven sampling (RDS) technique. RDS analyses were performed to provide estimates for the key outcome of interest. More than a third (34.5%) had never been tested for HIV, whereas 27.5% and 38.0% had their most recent HIV test more than three months and within the past three months from the time of interview, respectively. Young MSM who reported high self-efficacy (adjusted relative risk ratio [ARR]=7.35, 95%CI = 2.29–23.5) and moderate self-efficacy (ARR = 8.61, 95%CI = 3.09–24.0) were more likely to report having tested for HIV in the past three months compared to their counterparts who reported low self-efficacy. Findings highlight a positive association between self-efficacy and HIV testing uptake, indicating a potential causal relationship. Further research is needed to examine the direction of this association and inform future public health interventions targeting YMSM in Myanmar.