We reviewed 94 patients with Rathke's cleft cyst (RCC) who were surgically treated at Nippon Medical School Hospital between December 1995 and July 2009 to clarify the effect of surgery on their endocrine function. In our statistical analysis we considered their age and sex, the cyst volume, and preoperative MRI findings. Using simple linear- and multiple regression analysis we evaluated the association between these factors and their preoperative hormone baseline levels. To assess pre- and postoperative anterior pituitary function we subjected the results of various hormone loading tests to the Wilcoxon rank sum test. Surgery improved headache and visual impairment in most patients and elevated PRL levels were significantly normalized after surgery (p = 0.004). However, pre- and postoperative anterior pituitary hormone loading tests revealed that the levels of GH, TSH, LH, and FSH were not improved significantly by surgery. Although the ACTH loading test showed postoperative improvement, the change was not statistically significant. We suggest that RCC patients with headache or visual impairment are good candidates for surgery. We also recommend that patients with hyperprolactinemia and those with ACTH deficiency whose MRI findings reveal low-intensity on T1WI and high-intensity on T2WI are likely to benefit from surgery. In contrast, RCC patients with other hormone dysfunctions do not appear to benefit from surgical intervention.