Outcome data comparing patients with multiple primary invasive cutaneous malignant melanomas (MPMs) to single primary invasive cutaneous malignant melanomas (SPMs) show conflicting results. We have analyzed differences in disease-specific survival between these patients in a nationwide population-based setting. From the Swedish Melanoma Register, 27,235 patients were identified with a first invasive cutaneous malignant melanoma (CMM) between 1990 and 2007, followed-up through 2013. Of these, 700 patients developed MPMs. Cox proportional hazard regression was used for adjusted cause-specific hazard ratios (HRs). An interval of amp;lt;= 5 years between CMM diagnoses was significantly correlated to a decreased CMM-specific survival in Stage I-II MPM-vs. SPM-patients (HR 1.32; 95% CI 1.04-1.67; p=0.02). MPM-patients with longer time interval between diagnoses experienced similar risk of CMM-death as SPM-patients. The risk of CMM-death increased by almost 50% above the expected outcome according to stage of the index CMM by the diagnosis of a second CMM (HR 1.48; 95% CI 1.19-1.85; p amp;lt; 0.001). MPM vs. SPM-patients had a worse outcome (HR 1.38; 95% CI 1.05-1.83; p=0.001). This emphasizes the importance of prevention efforts in SPM-patients to decrease the risk of subsequent CMMs and has implications for more vigilant follow-up in MPM-patients.