Tinder, also known as the “hook-up app” is the leading online dating application. In this study, we explored the reasons for using Tinder when seeking opportunities for casual sex. We asked whether sexual disgust sensitivity and sociosexuality predict Tinder use with motivation for casual sex. We also tested if gender moderated this relationship. Results of the data collected from 169 Tinder using Amazon Mechanical Turk workers revealed that sexual disgust sensitivity and sociosexuality were predictors of motivation to use Tinder for casual sex. The participants with higher sexual disgust sensitivity reported a lower motivation while the participants with higher sociosexuality reported a higher motivation for casual sex in their Tinder usage. While this model explained the motivation for men, a different model explained women's motivation. Sociosexuality mediated the relationship between sexual disgust sensitivity and the motivation to use Tinder for casual sex for women Tinder users. Results are discussed from an evolutionary perspective.