Nonmelanotic skin cancer is the most common human neoplasia and its incidence is rising. The completeness of resection is the most important quality feature of surgical treatment of nonmelanotic skin cancer, as a complete resection distinctly reduces local recurrence. In this trial, we analyze the incomplete resection rate of nonmelanotic skin cancer (N = 524) through plastic surgery assistant doctors in the first 3 years of surgical training. We find that the incomplete resection rate of nonmelanotic skin cancer decreases significantly (P = 0.026) from mean 12.1% in the first year of training to mean 5.7% in the third year of training, despite a gain in difficulty level concerning tumor localization. Moreover, we identify the following tumor features as a risk factor for incomplete resection: facial tumors (P = 0.034), recurrent lesions (P = 0.032), and the tumor class of the superficial basal cell carcinoma (P = 0.010). We prove that complete excision of nonmelanotic skin cancer distinctly depends on the surgeon's experience level.