This article presents the development of a theory- and evidence-based internet hiv-prevention program for dutch men who have sex with men (msm) they have met on the internet. The program is based on a protocol called intervention mapping (im), which includes six steps. In step 1 of im, we conducted a needs assessment. In step 2 we established program objectives to get e-dating msm to use condoms consistently. In step 3 we translated theoretical methods into practical strategies. In step 4 we integrated the strategies into an intervention called gay cruise in which virtual pursers introduced participants to the strategies. In step 5 we discussed large-scale implementation. And in step 6 we discussed process and effect evaluation. We conclude that im can be a helpful tool for developing and improving internet hiv-prevention interventions.