Pituitary adenomas account for approximately 10% of clinically apparent intracranial neoplasms and are associated with increased morbidity and mortality. In Oman, there is limited data about pituitary adenomas. This study aims to assess the prevalence and clinical characteristics of pituitary adenomas subtypes and to explore possible factors associated with increased adenoma size among patients with pituitary adenomas in a tertiary center in Oman. This is a cross-sectional study involving record review. Patients with pituitary adenomas were identified by reviewing the medical records of all patients attended the neuroendocrine clinic at the National Diabetes and Endocrine Center between March 2013 and October 2016. Data related to adenoma subtypes, demographic, clinical characteristics and MRI features was collected. SPSS was used to analyze the data. A total of 224 patients diagnosed with pituitary adenoma were identified with female predominance. The overall mean age was 30.8 ±11.5 years (age range 14-75 years). Prolactinoma was the most prevalent subtype (68.8%), followed by non-functioning adenomas NFA (23.7%), GH secreting adenomas (6.3%). Only two patients with Cushing’s disease and one patient with TSHoma were identified. Microadenomas were common and constituted 55%. The most prevalent symptoms were headache (n=141; 62.9%), menstrual disturbance (n=96; 42.8%), galactorrhea (n=58;25.9%) and visual field defect (n=49;21.9%). Adenoma size was associated with age and gender. This study is the second study in Oman highlighting the prevalence and characteristics of subtypes of pituitary adenomas. The study showed that Prolactinomas were the most prevalent subtype, followed by non-functioning adenomas. Microadenomas were more common especially in young female patients. This study helps clinicians understand the epidemiological and clinical characteristics of pituitary adenomas in Oman and guides further analytical future studies.