Background: The thalamic tumors were less common in adults and this study aimed to determine the clinical features, surgical approaches, and outcomes of adult thalamic tumors, which have not been well-described in the literature. Methods: We reviewed the clinical presentation, surgical approach, perioperative mortality and morbidity, and outcomes of 111 operated patients (71 males, 40 females; mean age at presentation, 33.4 +/- 13.2 years) with unilateral thalamic tumor. Results: The most common clinical presentations were increased intracranial pressure (65 %) and motor deficits (40 %). Five surgical approaches were used depending on tumor location; the most common was the transparieto-occipital approach (47.7 %). According to peri-and post-operative magnetic resonance imaging findings, the tumors were totally resected in 29 cases (26.1 %), subtotally resected in 54 cases (48.6 %), and partially resected in 21 cases (18.9 %). Five patients died during the perioperative period (4.5 %, 5/111). The most common morbidity was motor deficits (21.7 %, 23/106). According to histological findings, there were 50 high-grade and 61 low-grade tumors. Median survival of patients with low-and high-grade tumors were 40 and 12 months, respectively (mean follow-up, 37.3 months). Survival was significantly longer in cases of total or subtotal resection (median, 28 months) compared to partial resection or biopsy (median, 12 months). Survival was poorer in adults than in previous reported pediatrics. Conclusions: Surgical treatment of adult thalamic tumors must be individualized according to tumor location. Low-grade tumors and total/subtotal resection seem to be predictors of better surgical outcomes. Nevertheless, the outcome of adult patients were still worse than pediatric patients.