We analyzed nationally and internationally recognized clinical practice guidelines for melanoma skin cancer to compare their therapeutic and diagnostic strategies. We considered internationally recognized melanoma skin cancer guidelines from the United States (American Academy of Dermatology), Germany (S3-Leitlinie Melanom), and Australia (Cancer Council Australia). We found widespread agreement in diagnostic approaches for cutaneous melanoma, especially in surgical intervention and therapy for regional lymph node involvement. The first difference encountered was the German guidelines advising lymph node ultrasound from stage IB, whereas the US and Australian guidelines recommend it only when sentinel lymph node biopsy is not possible or denied by the patient. A different approach was observed in relation to the assessment of tumor marker S100B in stage III of cutaneous melanoma. The German guidelines advocate for the incorporation of S100B in baseline surveillance, whereas Australia and the United States do not. Although there were some further minor differences, apart from the aforementioned two, all three guidelines under scrutiny exhibit a substantial level of agreement.