Cyclic vomiting syndrome (CVS) is a chronic disorder characterized by episodic nausea and vomiting. A large proportion of patients use marijuana to control their symptoms. Several case reports implicate marijuana as a cause of intractable vomiting with compulsive hot water bathing considered pathognomonic of "cannabinoid hyperemesis." We sought to examine the relationship between marijuana use and CVS. Patients >18 years of age diagnosed by a health care provider were invited to participate in an anonymous internet-based survey. A total of 514 patients participated and 437 completed questions about marijuana use. Mean age was 34 ± 12 years with patients being predominantly female (63%), Caucasian (92%) and from the USA (82%). Nineteen percent never used marijuana and 81% did. Fifty-four percent used marijuana for health issues and 43% for recreational purposes. Users stated that it improved nausea, appetite, general well-being, stress levels and vomiting. Users were more likely to be male and have an associated anxiety disorder. Sixty-seven percent of patients reported taking hot showers/baths for symptom relief, and this was associated with marijuana use. (OR 2.54, CI 1.50-4.31, P = 0.0006). Eighty-one percent of patients with CVS who completed an internet survey reported frequent use of marijuana. With marijuana use, patients noted the greatest improvement with stress levels, appetite and nausea. Marijuana users were more likely to be male and have associated anxiety. Hot showers were not pathognomonic of marijuana use though they were more likely to be associated with its use.