To assess the patient's capability of performing a correct skin-check examination we investigated the association of melanoma detection pattern with Breslow thickness, by melanoma body area. In this prospective observational study, patients with primary cutaneous melanoma who presented at the Department of Dermatology at the University of Florence between January 2000 and November 2011 were interviewed as part of their clinical data recording procedure at the time of their final histopathological diagnoses of melanoma. With the aim of evaluating a self skin-check, we included patients with melanoma in the anterior part of the trunk (abdomen and chest area), which is generally considered visible in the mirror, and the posterior part of the trunk, which is a more complex area to be self-checked. The treating physician specifically questioned all patients about who had first detected or suspected the lesion that resulted in the histological diagnosis of melanoma in order to compare those who had self-detected (SD) their melanoma with those who had discovered their melanoma during a regular skin-check (RSC) with a dermatologist. A total of 186 melanoma patients were analyzed, with 67% (n=125) of melanomas located on the back and 33% (n=61) in the chest and abdominal area; the majority (55%, n=103) were in the SD group. The median Breslow thickness of the SD group was significantly greater than that of the RSC group: 0.60 versus 0.50 mm (P<0.0001). In the posterior trunk, the frequency of thick melanomas (Breslow≥1.00 mm) was significantly greater in the SD group than in the RSC group (34 vs. 11%; P=0.003), whereas there was no difference in the frequency of thick melanoma by detection patterns in the anterior trunk. Given the influence of the body area in detecting threatening melanoma, we should encourage people to obtain dermatological skin-checks more often. Skin self-examinations cannot be sufficiently accurate.