Studies on internet-administered cognitive behavior therapy (ICBT) frequently use several different sources of recruitment, yet no study has investigated whether different recruitment sources produce different clinical and demographic profiles among participants. Using data from a large sample (n = 982) seeking ICBT for depression, we compared these characteristics on the basis of self-reported recruitment source. Recruitment sources that imply more active treatment-seeking behaviors (Google searches, viewing postings on mental health websites) presented more severe depression and anxiety than those recruited through more passive sources of information (newspaper advertisements, referrals by friends and family). In addition, a number of demographic differences between groups were found. These findings have important implications for ICBT research projects and clinical programs who employ open recruitment procedures and multi-modal recruitment strategies, and who wish to recruit representative samples or target specific subgroups. Replications in other countries will however be required to establish cross-cultural patterns.