The main objective in this study was to examine Facebook and Google advertisements as a recruitment strategy in the “European Web Survey on Drugs: patterns of use” project. The Facebook recruitment campaigns invited individuals who lived in Croatia, the Netherlands or Switzerland, who were over 18 years of age and who had consumed at least one drug (cannabis, MDMA / ecstasy, (meth)amphetamines or cocaine) in the past 12 months, to complete a web survey about their patterns of drug use. The Google campaign was focused on participants that lived in Croatia, who were at least 18 years old and had consumed one of the aforementioned drugs in the last year. All campaigns applied a cost per click model. Results showed that the Facebook campaign had the highest number of clicks on the advertisement in Croatia (HR: 14,791; SW: 4,292; NL: 707), as well as eligible participants (HR: 3,581; SW: 1,281; NL: 394), while the Netherlands had the lowest cost per participant (EUR 0.25). The Google campaign in Croatia resulted with 5,677 clicks. The average cost per click differed during the campaign (HRK 0.36-2.73), and a higher budget, did not result in a higher number of clicks. It can be concluded that Facebook and Google advertisements resulted in a broad reach with a reasonable budget, therefore these strategies present a useful tool for recruiting large numbers of participants in surveys on the sensitive topic of drug use.