Introduction: Psoriasis is a chronic-immune-mediated disease affecting 2–4% of the western population. The disease is associated with several co-morbidities including an increased risk of cancer. Concerns have been raised whether psoriasis itself, the psoriasis-associated risk factors, or the treatment of psoriasis might lead to an increased risk of cancer. Areas covered: We reviewed the literature on cancers associated with psoriasis and discuss some of the potential mechanisms behind the observed associations. Expert opinion: Patients with psoriasis have an increased risk of cancers overall and some site-specific cancers especially non-melanoma skin cancer, lymphoma, and lung cancer. The increased risk is most likely due to a combination of the chronic low-grade inflammation in psoriasis, risk factors for cancer associated with psoriasis, and the treatment of psoriasis. Future research should investigate the contribution of the individual mechanisms. Additionally, multiple new specific immunomodulatory treatments for psoriasis have been introduced during recent years and it is important to monitor and investigate whether these treatments confer an increased risk of cancers. Lastly, as patients with psoriasis have an increased alcohol use, smoke more than the general population and as psoriasis has been linked to obesity, promotion of a healthy lifestyle is key in the prevention of certain cancer types.