Objective To summarize X-ray and CT findings of soft tissue and bone infections secondary to acquired immunodeficiency syndrome (AIDS).Methods The data of X-ray and CT findings of soft tissue and bone infections in 18 patients with AIDS were retrospectively collected and analyzed.Results Of 18 patients with AIDS,the CT features of soft tissue demonstrated that subcutaneous patchy high density in 1 case which considered as cellulitis,round low density lesions with ring enhancement in 6 cases which considered as soft tissue abscesses,heterogeneous density lesions with peripheral enhancement in 1 case which considered as pyomyositis.Of 18 patients with AIDS,septic arthritis was found in 4 cases involving knee lesion in 3 cases and hip lesion.In the 4 case,the X-ray films showed bony destruction in 2 cases and the CT showed bone destruction in 3 cases and arthroedema in 4 cases.Of 18 patients with AIDS,osteomyelitis was found in 9 cases of which tuberculosis was considered in 8 cases and vertebral involvement in 6 cases.In the 9 cases,the X-ray films and CT displayed bony destruction,hyperostosis,small sequestra,and intervertebral space narrowing.Of 18 patients with AIDS,costal lesions were found in 3 cases in which the CT showed expandable bony destruction.Of 18 patients with AIDS,ilium and cacroihac joint lesions were found in 1 case in which the X-ray films and CT showed bony destruction,sequestra,and joint widening.Of 18 patients with AIDS,chronic pyogenic osteomyelitis of femur was found in 1 case in which the X-ray films showed bony destruction,hyperostosis osteosclerosis,and periosteal reaction.Conclusion The X-ray and CT features of soft tissue and bone infections secondary to AIDS are characterized.The X-ray and CT are useful tools to early diagnose soft tissue and bone infections secondary to AIDS.