Introduction: Percutaneous intramedullary K. wires fixation and mini-plates fixation are reasonable options for treating unstable metacarpal fractures as they provide anatomical reduction and rigid fixation, which is adequate to permit early mobilization. The aim is to compare between mini-plates and Kirschner wires in management of unstable metacarpal shaft fractures in adults. Patients and Methods: All patients (n=30) included in this prospective comparative study were managed and followed up at Al-Azhar University Hospital from January 2019 to February 2020. Thirty patients with fracture of shaft metacarpal were divided into 2 groups: group A (n=15) were managed by percutaneous intramedullary Kwires and group B (n=15) were managed by mini-plates. Results: Twenty-seven patients were males and 3 were females. Dominant hand affection were in 20 patients. All patients had a complete union between 4-8 weeks for group A with average of 6 weeks and 6-10 weeks for group B with average of 8 weeks. The total result according to TAF score, Quick DASH score, and handgrip was excellent in 10 cases, good in 4 cases, and fair in 1 case in group A, while group B was excellent in 10 cases, good in 3 cases, fair in 1 case and poor in 1 case. Conclusion: Both techniques are highly effective for fixation of metacarpal shaft fractures. Mini-plate fixation provides rapid recovery of hand function and K-wire fixation allows a wide range of hand motion and soft tissue preservation.