Background: As the incidence of cutaneous melanoma continues to rise, more individuals will be at risk for developing second primary melanomas. We hypothesize that patient education and follow-up surveillance will lead to the early detection of subsequent primary melanomas as demonstrated by a decrease in Breslow thickness at diagnosis. Methods: A computer-based investigation was performed to identify patients who had developed a second primary melanoma following treatment of in situ and American Joint Commission on Cancer (AJCC) Stage I or II melanoma. Patients are routinely educated on the increased risk of developing a second primary lesion and characteristic clinical features of melanoma. Patient surveillance was performed on a regular basis. Differences in Breslow thickness between the initial and subsequent primary melanomas were analyzed by a paired t-test. Results: Among 877 individuals identified in the Mount Sinai School of Medicine Department of Dermatopathology database with in situ or AJCC Stage I or II melanoma, 111 developed a second primary melanoma. The mean thickness was 0.239 ± 0.661 mm for the initial melanoma and 0.1135 ± 0.319 mm for the subsequent melanoma. By paired t-test, the difference in tumor thickness was statistically significant (P = 0.019). Conclusions: Upon analysis of our data, subsequent primary cutaneous melanomas were found to be significantly thinner than initial primary melanomas at the time of diagnosis. This suggests that earlier diagnosis may be the result of patient education and careful follow up. Counselling on the risk of developing a second primary melanoma, education regarding clinical characteristics of melanoma, and routine lifelong follow up should be provided to all patients diagnosed with a cutaneous melanoma.