Background: The risk of melanoma and hematologic cancers in patients with psoriasis is controversial. Objective: We sought to assess the risk of melanoma and hematologic cancers in patients with psoriasis, and the association with different treatments. Methods: We used case-control and retrospective cohort designs to determine melanoma or hematologic cancer risk in patients with psoriasis. Risk with treatment type was assessed using Fisher exact test. Results: Patients with psoriasis had 1.53 times greater risk of developing a malignancy compared with patients without psoriasis (P < .01). There were no significant differences in malignancy risk among patients treated with topicals, phototherapy, systemics, or biologic agents. Patients with psoriasis and malignancy did not have significantly worse survival than patients without psoriasis. Limitations: It is possible that patients developed malignancy subsequent to the follow-up time included in the study. Conclusion: Patients with psoriasis may experience an elevated risk of melanoma and hematologic cancers, compared with the general population. The risk is not increased by systemic or biologic psoriasis therapies.