Modular femoral and acetabular components are frequently used in hip arthroplasty. Although the use of modular components offers many advantages, the increased number of components leads to a high risk of disassembly. Disassociation of the femoral head and neck is a rarely reported complication in the literature. This case report depicts a patient with non-traumatic early disassociation of the femoral head and neck components following total hip revision arthroplasty. Femoral head-neck disassembly in early postoperative period may occur due to manufacturing error or insufficient impaction. If sufficient impaction is thought to be achieved, manufacturing errors should be kept in mind as potential underlying reasons for femoral head-neck dissociation.