Introduction. The use of social networking sites (SNS) sometimes acquires an addictive-like quality, often referred to as problematic use of SNS. This condition overlaps with problematic (addictive-like) use of smartphones, as the latter are commonly used for online social networking in addition to other activities that may gain addictive-like qualities. There is ample evidence that problematic use of smartphones and SNS is associated with poorer mental health, but research on associations with sexual function is scarce. Thus, we examined if sexual difficulties are related to problematic use of SNS and smartphones. Methods: Data from four studies conducted in Portugal were collapsed, resulting in 946 women and 235 men providing data on sexual function and problematic use of smartphones, and in 536 women and 194 men providing data on sexual function and problematic use of SNS. Female sexual function was assessed with the Female Sexual Function Index (FSFI) and the Female Sexual Distress Scale – Revised (FSDS–R). Male sexual function was assessed by the International Index of Erectile Function (IIEF). Problematic smartphone use was measured by the Smartphone Addiction Scale – Short Version (SAS–SV). Problematic use of SNS was measured by the Internet Addiction Scale (IAT) specifically adapted to online social networking.Results: In women, problematic use of smartphones and SNS correlated with lower sexual arousal, difficulties lubricating, difficulties having orgasms, sexual dissatisfaction, coital pain, and greater sexual distress. In men, problematic use of smartphones and SNS correlated with lower erectile function. Men’s problematic use of SNS correlated additionally with lower desire, intercourse dissatisfaction, overall sexual dissatisfaction, and more difficulties having orgasms. In a subsample of 311 women and 94 men with data on use of smartphones and SNS, multiple regressions predicting sexual function domains from age, problematic smartphone use, and problematic use of SNS, were performed. In women, problematic use of SNS independently predicted lower arousal, dissatisfaction, pain, and more sexual distress. Problematic use of smartphones independently predicted more difficulties lubricating. In men, problematic use of SNS independently predicted lower erectile function, intercourse dissatisfaction, and overall dissatisfaction.Discussion: Addictive-like use of SNS might be a risk factor for sexual difficulties. Our findings corroborate previous research.