Objective: To study the clinical characteristics of growth hormone (GH)-secreting pituitary adenoma with concomitant colorectal cancer. Methods: The clinical and pathological data of 8 patients with GH-secreting pituitary adenoma and concomitant colorectal cancer admitted from 2006 to 2011 were retrospectively analyzed. Results: There were 6 male and 2 female patients, and the median age was 59 (48-69) years. The history of acromegaly caused by pituitary tumor of the patients ranged from 10 to 30 years. Two patients had undergone treatment for pituitary adenoma. The serum levels of hormones were detected and MRI/CT examinations were performed before surgery. All patients were diagnosed as having colorectal cancer by colonoscopic biopsy and all underwent radical operation for colorectal cancer. The clinical stages of the tumor were Dukes B and C. Adjuvant chemotherapy was given in all patients after surgery. The postoperative complications included pulmonary infection, hypertension, hyperglycemia, hypokalemia, etc., which were all resolved by symptomatic treatments. No anastomotic fistula or abdominal infection occurred. One case was self-discharged from hospital against advice (and then was lost to follow-up). The other 7 cases were followed up for 2 to 44 months and all were alive. Conclusions: For patients with GH-secreting pituitary adenoma and concomitant colorectal cancer, the comprehensive treatments for colorectal cancer shoud be adopted first, and later the pituitary adenoma is treated according to the patient’s situation.