Gastroesophageal reflux (GER), through the occurrence of gastroesophagopharyng eal reflux (GEPR), is an established cause of several otorhinolaryngological (OR L) manifestations. It has been suggested that unexplained excessive throat phleg m might also be a manifestation of GER, but formal evidence is lacking. The aim of the present study was to investigate the prevalence of GER as well as duodeno gastroesophageal reflux (DGER) in consecutive patients with chronic complaints o f excessive throat phlegm. Fifty-nine consecutive patients with chronic unexpla ined excessive throat phlegm, transparent in 33 patients (TTP) and yellow in 26 patients (YTP), underwent gastrointestinal endoscopy, 24-hr dual esophageal pH monitoring, and fiberoptic DGER monitoring. Proximal esophageal DGER monitoring was performed in seven YTP patients and analysis of bile acids in throat phlegm was performed on 16 samples. The effect of high-dose acid suppressive therapy w as evaluated at 2-week intervals. Endoscopy and pH monitoring established a dia gnosis of pathological GER in 75%of the patients. Pathological DGER was present in 56%of the patients and this was associated with YTP. Proximal DGER exposure was high in all investigated subjects and chemical analysis revealed a median b ile acid concentration of 0.184 μM in nine YTP samples and no detectable bile a cids in seven TTP samples. After a median of 4 weeks of acid suppressive therapy , most patients improved and 61%became asymptomatic. YTP patients were more lik ely to require maintenance acid suppressive therapy than TTP patients. Unexplain ed excessive throat phlegm is a sign suggestive of GER and GEPR, and unexplained yellow throat phlegma sign suggestive of duodenogastroesophagopharyngeal reflux (DGEPR). It has been suggested that that unexplained excessive throat phleg m might also be a manifestation of GER, but formal evidence of lacking. The aim of the present study was to investigate the prevalence of GER as well as duodeno gastroesophageal reflux (DGER) in consecutive patients with chronic complaints of excessive throat phlegm. Fifty-nine consecutive patients with chronic unexplained ined excessive throat phlegm, transparent in 33 patients (TTP) and yellow in 26 patients (YTP), underwent gastrointestinal endoscopy, 24-hr dual esophageal pH monitoring, and fiberoptic DGER monitoring. Proximal esophageal DGER monitoring was performed in seven YTP patients and analysis of bile acids in throat The effect of high-dose acid suppressive therapy w as evaluated at 2-week intervals. Endo Scopy and pH monitoring established a diagnosis of pathological GER in 75% of the patients. Pathological DGER was present in 56% of the patients and this was associated with YTP. Proximal DGER exposure was high in all investigated subjects and chemical analysis revealed a median After a median of 4 weeks of acid suppressive therapy, most patients improved and 61% became asymptomatic. YTP patients were more lik ely to require maintenance acid suppressive therapy than TTP patients. Unexplain ed excessive throat phlegm is a sign suggestive of GER and GEPR, and unexplained yellow throat phlegma sign suggestive of duodenogastroesophagopharyngeal reflux (DGEPR).