Background We evaluated the prevalence of motion restriction and axillary web syndrome (AWS) after sentinel node biopsy (SNB) and axillary clearance (AC) in a prospective study. AWS is a self-limiting cause of early postoperative morbidity after axillary surgery. Limited range of motion associated with palpable cords of tissue in the axilla are typical for AWS. Methods Altogether 85 breast cancer patients who underwent SNB only (49 patients) or SNB and AC (36 patients) were examined before and after surgery. The range of shoulder flexion and abduction and the presence of AWS were registered. Results The range of shoulder movements was restricted in 24 (45%) patients after SNB only and in 31 (86%) patients who also underwent AC ( P = 0.002). AWS was encountered in 10 (20%) patients with SNB and in 26 (72%) with AC ( P <0.00005). Conclusions In the SNB group, significantly less early postoperative morbidity was observed.