To investigate the clinical manifestations, imaging, pathology, and prognosis of orbital solitary fibrous tumors (OSFTs). In addition, the surgical incisions and the treatment outcomes were also evaluated. A total of 89 patients with pathologically confirmed primary OSFTs were enrolled onto this study. Clinical and histopathological characteristics, imaging data, treatment modalities, and follow-up time, including tumor recurrence and death, were documented. The outcome measures included overall survival and disease-free survival time. Among 89 eligible cases, the median age of presentation was 39 years (range: 5-80 years) at the initial diagnosis. The most common presenting symptom was painless proptosis (54, 60.67%), then palpable mass (31, 34.83%), swelling (29, 32.58%), and impaired ocular motility (27, 30.34%). Tumor-related severe impaired vision was found in 11 patients (12.36%), including no-light-perception blindness (6, 6.74%), light-perception (2, 2.25%), and hand-movement (1, 1.12%). The preoperative imaging (computed tomography and magnetic resonance imaging) accurate diagnostic rate of OSFTs was 17.98% (16, 95% CI: 0.098-0.261), and misdiagnosis rate was 25.84% (23, 95% CI: 0.166-0.351). Grossly intact masses were excised for 27 patients (30.34%). Among the 89 patients, 33 (37.08%) were recurrences, and the median of these recurrent patients' interval between the first and the last operation was 7.33 years (range: 0.12-29.69 years). In 81 patients with complete follow-up data, the median course of the disease was 9.64 years (range: 1.55-33.65 years) from the onset OSFT. The overall survival rate of the 81 patients was 93.83% with a median course of 8.48 years (range: 0.38-30.4 years) from diagnosis of OSFT, and the disease-free survival rate of 81 patients was 91.36% with a median follow-up of 4.76 years (range: 0.08-19.22 years) after the last surgery. Of all the 81 patients, 5 patients (6.17%) developed local recurrence, and 3 patients (3.70%) died from tumor-related diseases, including pulmonary metastasis (2, 2.47%) and complications from intracranial lesions (1, 1.23%). Ten patients (11.24%) received postoperational radiation therapy, including 125I seeds implantation (5, 6.17%) and external beam radiotherapy (5, 6.17%), and remained no recurrence. In this series, OSFTs showed long courses and easy recurrence. Although it was very important to choose a proper surgical incision for intact resection of OSFTs at the initial surgery to avoiding recurrence, preoperative imaging is of very limited use since it is not able to identify OSFTs effectively. Postoperative radiotherapy may be beneficial to reduce the recurrence of OSFTs with malignant pathologic features.