Atypical lipomatous tumor (ALT) is a rare, well-differentiated and low-grade liposarcoma originating in deep soft tissue compartments of extremities and trunk. The optimal surgical treatment in the upper extremity is still controversial. Some Authors suggest the wide excision of the mass including the sacrifice of the muscle-surrounding tumor, others recommend the marginal resection of the lesion.We report a case of a 58-year-old patient who underwent the "simple" marginal resection of an ALT in the forearm by sparing the muscles surrounding the lesion. After 60 months, the patient is asymptomatic with no recurrence of the mass and a total recovery for activities of daily living.Based on our experience the simple marginal resection "en bloc" is the gold standard for skilled hand surgeons to preserve neurovascular structure with no recurrences at medium-term follow-up.