To evaluate the long-term trends in mortality rates attributed to AIDS and sexually transmitted infections (STIs) due to unsafe sexual behavior in China from 1990 to 2019.

Data on AIDS and STI mortality attributed to unsafe sexual behavior were sourced from the Global Burden of Disease Study (GBD) 2019. An age-period-cohort model was employed to assess potential age, period, and cohort effects on long-term trends.

From 1990 to 2019, the overall annual percentage change in mortality rates attributed to unsafe sexual behavior was 3.4% (95%CI: 3.0%-3.7%) for females and 6.4% (95%CI: 6.0%-6.8%) for males in China. Among different age groups, males aged 25 to 79 showed a higher annual percentage change than females (P<0.05). In the reference cohort, male mortality rates increased with age, while female mortality rates declined after the age of 79. The period mortality risk for males exhibited a consistently increasing trend, whereas the period mortality risk for females slightly decreased between 2010 and 2014 but increased thereafter. Mortality risks for both males and females born after 1925-1929 showed an upward trend over time.

Between 1990 and 2019, there was an increase in mortality rates attributed to AIDS and STIs due to unsafe sexual behavior among both males and females in China. Unsafe sexual behavior remains a significant issue in the prevention and control of AIDS and STIs. Strengthening sexual education, promoting condom use during sexual activities, and ensuring cleanliness in sexual behavior are essential.