OBJECTIVE Rathke cleft cysts (RCCs) are benign lesions originating from remnants of the Rathke pouch. RCCs have been classified into the intrasellar-based or purely suprasellar types. This research aims to study the optimal treatment nuances and evaluate the surgical outcomes of this distinct type of RCCs. METHODS This study retrospectively reviewed 36 patients with purely suprasellar RCCs who were treated by expanded endonasal endoscopic approach (EEA) from September 2018 to January 2021. The demographic data, presenting symptoms, endocrine status, imaging findings, operative details, and surgical outcomes were analyzed. RESULTS According to the relationship with pituitary stalk, the suprasellar RCCs can be divided into 2 different growth patterns: intrastalk cyst (ISC, 52.8%) and extrastalk cyst (ESC, 47.2%). Preoperative endocrine dysfunctions occurred more in patients with ISC than ESC (P = 0.007), which are characterized by hypoadrenalism (P = 0.004) and hypogonadism (P = 0.008). Operation exerted different impacts on endocrine functions between ISC and ESC (P = 0.012). When identifying by single hypothalamic-pituitary axis, 4 patients with normal endocrine function developed a new hormonal deficit, 14 patients with preoperative endocrine dysfunctions benefited from our expanded EEA surgical treatment, and 3 of them completely recovered from the endocrinopathy after surgery. The postoperative endocrinopathy was positively associated with the numbers of preoperative abnormal endocrinal axes. Thirty-four (94.4%) patients had achieved gross total resection. Pituitary stalk was intactly preserved in 23 of 36 patients (63.9%), partly preserved in 10 patients, and not preserved in 3 patients. CONCLUSIONS Purely suprasellar RCCs are a distinct type of RCCs, which originate from the pituitary stalk above the diaphragmatic sellae, and the treatment strategy via expanded EEA is a rational choice. Classification based on growth patterns would be beneficial to reduce endocrine disorders after surgery.