Objective: To determine the effects of dry needling (DN) in active myofascial trigger points in the teres major muscle compared to an untreated control group in pain during throwing actions, shoulder range of motion (ROM), strength, and extensibility of the tissues in professional handball (HB) athletes. Methods: A randomised, single-blinded, controlled clinical trial was designed. Thirty HB athletes with shoulder pain were randomly assigned to the DN group (n = 15) or control group (n = 15). The DN group received a single session of ultrasound-guided DN technique in the teres major muscle. The control group received no intervention. Pain intensity during throwing actions (Numeric Pain Rating Score), shoulder ROM (inclinometer), isometric strength (hand-held dynamometer), and extensibility (inclinometer) were measured before and after treatment. Results: DN group showed statistically significant improvements with large effect sizes for pain intensity (p < 0.001; E.S: 1.3), internal rotation ROM (p < 0.001; E.S: 3.0) and extensibility (p < 0.001; E.S: 2.9) compared to the control group. No statistically significant differences were found for isometric strength (p > 0.05). Conclusion: A single session of DN in the teres major muscle was effective for improving pain intensity during throwing actions, internal rotation ROM and extensibility in HB athletes with shoulder pain.