Surgical excision of melanocytic lesions is a common procedure. Incomplete excisions cause unnecessary distress and may lead to further surgery. This study reveals that approximately 1 in 10 melanocytic lesions are incom pletely excised. Risk factors associated with higher incomplete excision rates are: naevi and melanomas in the head and neck area; surgery performed by general practitioners; punch excisions, and excisions of non-dysplastic naevi. Thus, larger surgical margins may be required in the head and neck area. Furthermore, general practitioners may need better surgical training in this procedure and updates on surgical guidelines. Lastly, the use of punch excisions for these lesions is not recommended.Incomplete excisions of melanocytic lesions occur despite the intention of complete removal. The aim of this study was to determine the incomplete excision rates for benign and malignant melanocytic lesions and the associated risk factors. Demographic, clinical, and histo pathological data possibly associated with incomplete excision were collected from 2,782 consecutive excisions between 2014 and 2015. Of these, 269 melanocytic lesions (9.7%) were incompletely excised. Multivariate analysis revealed the following risk factors for significantly higher incomplete excision rates: lesions located in the head and neck area (odds ratio (OR) 3.95, 95% confidence interval (95% CI) 2.35-6.65), surgery performed by general practitioners (OR 3.01, 95% CI 2.16-4.19), the use of a punch excision technique (OR 2.83, 95% CI 1.96-4.08), and excision of non-dysplastic naevi (OR 1.58, 95% CI 1.11-2.23). In conclusion, more caution should be taken when excising melanocytic lesions in the head and neck area, general practitioners require more surgical training, and punch excisions of melanocytic lesions should be avoided.