Introduction: Bergstrom needle muscle biopsies have been used by exercise physiologists for over 35 years but have been less accepted by neuromuscular clinicians due to size concerns. Methods: We retrospectively reviewed over 13,500 muscle Bergstrom needle biopsies done over a 21-year period to determine sampling success, patient/subject experience, and complications. We compared sample yield between two different needles (Bergstrom vs. UCH), with and without suction modifications. Results: Needle biopsies adequate for histology and enzymology were obtainable from the vastus lateralis, deltoid, biceps brachii, soleus, and medial gastrocnemius muscles, with a success rate of >99.9% and a minor complication rate of 0.15%. Approximately 450 muscle fibers were submitted for histologic assessment; suction modification and use of the Bergstrom vs. UCH needle were associated with larger sample size (P < 0.05). Conclusions: The suction-modified Bergstrom needle muscle biopsy technique is safe and provides an adequate sample size for histologic, ultrastructural, DNA, and enzyme analysis. Muscle Nerve 43: 717-725, 2011