Peritoneal mesothelioma is an uncommon malignancy affecting approximately 300 new patients annually in the United States. Due to its low incidence, prospective clinical trials specific to this disease are scant. Recommendations regarding systemic therapy are mostly extrapolated from clinical trials conducted among patients with pleural mesothelioma. At present, the recommended first-line systemic treatment options may include immunotherapy with nivolumab plus ipilimumab or chemotherapy with pemetrexed plus either cisplatin or carboplatin. For second-line treatment, the other previously unchosen first-line option can be used. Off-label bevacizumab may be considered in combination with chemotherapy among carefully selected patients. The benefit of third-line treatment or beyond is less clear. Nonetheless, a number of single-agent regimens show modest activity. Anecdotal reports of children or young adults with peritoneal mesothelioma harboring ALK rearrangement have suggested the efficacy of ALK inhibitors for this rare population. In summary, there is a growing number of systemic therapy options for peritoneal mesothelioma. To gain a better insight into this disease, future prospective trials in mesothelioma should include more patients with peritoneal mesothelioma.