According to the Behavioural Immune System (BIS) theory, humans are motivated to avoid exposureto harmful pathogens. However, most sources of infection are impossible to avoid completely, leadingto the development of tools to reduce pathogen threat. Condoms are one example of an effective toolthat can be used to avoid exposure to sexually transmitted infections (STIs). Within this framework, itwould be expected that condom use would increase after the spread of a novel coronavirus (i.e.,COVID-19), but the evidence to date is inconsistent. The present study aimed to clarify theseinconsistencies by examining changes in condom use cross-culturally. First, Study 1 aimed to uncoverwhether condom use after the initial outbreak period was consistent with the BIS theory among anAustralian sample (N1 = 129). Contrary to the BIS, but inline with other findings in Australia, therewas a general decline of condom use. Second, Study 2 aimed to examine whether cross-culturalcondom use was consistent with the BIS. Sexually active participants (N2 = 3843) across 17 countrieswere asked about their condom use. Results revealed a significant decline in Canada, Portugal,Vietnam, Uganda, and Taiwan. Vaccination percentage and lockdown stringency were associatedwith this decline cross-culturally. In sum, there was no evidence supporting the BIS theory, and thesefindings continue to add concerns about the spread of STIs among young people during the pandemic.