Cutaneous malignant melanoma (CMM) ranks among the five most common cancers in young people in high-income countries and it features peculiar clinicopathological traits. Very few studies have addressed the quality of care and the costs for adolescents and young adults (AYA) population. To provide a comprehensive epidemiological and clinicopathological profile of CMM in AYA. The study also addresses the cost-of-illness and the diagnostic-therapeutic performance indicators by patient age category. This population-based cohort study included 2435 incident CMM (age range 15-65 years; age 15-39 = 394; age 40-65 = 2041), as recorded in 2015, 2017 and 2019 by the Regional Veneto Cancer Registry (Italy). Cramer's-V tested the strength of association between pairs of variables. The Kaplan-Meier method was used to test the association between age and survival rate. The clinical performance indicators were computed using the Clopper-Pearson exact method. In AYA patients (16.2%), CMM incidence rates increased significantly from 1990 to 2019. Low-stage CMM (p = 0.007), radial growth pattern (p = 0.026) and lower Clark levels (p = 0.007) prevailed; males had less advanced malignancies (p = 0.003), with the trunk as the most common primary site (67.5%); the lower limbs (32.6%) were the most common primary site for females (p < 0.001). Overall survival was better in AYA than adults. No significant difference was detected in the clinical management of the two age groups, with the only exception of the margin in wide local excision. The care costs were lower in AYA (€195.99 vs. €258.94, p = 0.004). In AYA patients, the CMM clinicopathological presentation shows a distinctive profile. The present results provide critical information for optimizing primary and secondary prevention strategies and for tailoring diagnostic therapeutic procedures to the peculiar profile of AYA CMM patients.