The aim of this prospective study was to evaluate clinical outcomes of MFAT injections in patients with hip OA. Results: No major complications were reported, and only three patients failed. The total WOMAC score significantly improved from baseline only at 1 month and 3 months, while VAS and HHS scores showed a significant improvement from baseline to all follow-ups. Conclusions: A single ultrasound-guided intra-articular MFAT injection represents a safe and promising option for hip OA treatment. However, the clinical benefit was partial, and better outcomes were observed in mild compared to moderate hip OA.