Introduction: The present study was conducted to evaluate the prevalence of trend and use of complementary and alternative medicine in patients referring to the Gastroenterology clinics in Mashhad.  
Methods: The present cross-sectional study was performed at Gastroenterology clinics affiliated with Mashhad University of Medical Sciences. The study began in December 2015 and ended in March 2017. The study subjects (n=751) were randomly selected from patients referring to Gastroenterology clinics in the city of Mashhad.  Patients responded to the questions through interviews. The collected data were analyzed by SPSS-16 statistical software.
Results: This study was conducted on 751 patients referring to gastroenterologists; of whom, 274 (48.36%) were male and 476 (38.63) were female. According to the results, the most popular complementary and alternative medicine treatments were respectively herbal medicine, cupping therapy and acupuncture. A significant difference was observed in the means at is faction with complementary and alternative medicine between those who believed in it and those who did not (p=0.001); but, no significant difference was detected in mean satisfaction with complementary and alternative medicine between patients with different occupations (p=0.193). There was also a significant difference in the number of patients between the group of patients receiving chemical medication and the group of patients receiving complementary and alternative medicine therapies (p=0.005). No significant difference was found in the level of satisfaction with complementary and alternative medicine between participants referring to the Gastroenterology clinics for different causes (p=0.431); nonetheless, the highest satisfaction was observed in patients with malignancy, and the lowest satisfaction was detected in patients with esophageal disorders.
Conclusion: This study indicated the high prevalence of complementary and alternative medicine in Iran. The worldwide popularity of complementary and alternative medicine should not be overlooked, therefore; current medical treatment systems need to be revised and modified