HIV exposure is one of the greatest sexual risks in young people, and condom use is the best protective measure. Despite the preventive efforts, trend in condom use is still unclear. This study examines the trend of condom use by gender in Spanish young people, in different sexual practices (vaginal, oral and anal), relationships (regular and casual) and having sex after drugs consumption during the two past decades (from 1999 to 2020). For this, 14,472 people who ranged from 17 to 40 years old (63.5% women) filled the AIDS Prevention Questionnaire in each year. In general, low condom use remains stable and even gets worse regardless of the type of sexual practice, relationship and the substance consumption. Regarding gender, this trend is worse in women who have been less likely to report condom use than men have. Moreover, older people have reported a minor frequency of condom use than the youngest people have done, except for anal sex. Therefore, it is necessary to analyze why, despite preventive efforts, condom use seems to decrease over time.