Communication about sexual health as means of promoting safer sex is particularly important to young people who are mostly at risk of STI and HIV infections. This research based work examine the effects of knowledge about HIV/AIDS and perceived self-efficacy related to practices of protective sexual behaviors on communication about sexual health among young partners selected from Teachers Training college in Mbeya, Tanzania. Participants of this work demonstrated high knowledge about HIV/AIDS and perceived self-efficacy related to practices of protective sexual behaviour. However, their communication about sexual health with their sex partners was found to be very low. This work also revealed that while knowledge about HIV/AIDS was not a statistically significant predictor of communication about sexual health, perceived self-efficacy was. The prevalence of low communication about sexual health among participants suggested that there is a need for examining and reviewing both the content and the process of HIV/AIDS school/college based programmes so as include aspects of sexual health communication as part of their components.