Introduction: Gastroesophageal reflux (GER) causes esophageal and extra-esophageal symptoms. Frequent extra-esophageal symptoms are cough, laryngospasm, laryngitis and asthma. Microand macro-aspiration are hypothesized pathophysiologic mechanisms. Aim: to compare the results obtained with two techniques that can measure reflux in the hypo-pharynx. Methods: The "Restech technique" evaluate the pH at the level of the hypo-pharynx through a probe with a pH-antimony sensor which is placed behind the soft palate. Mutichannel intraluminal impedance/pH-monitoring (MII/pH) records the passage gas and liquid reflux, and the pH of the latter, through a probe with 6 impedance sensors and 2 pH antimony sensors (the lower at 3 cm above the LES and the high at the level of hypo-pharynx). Ten adults patients (age 46.33 ± 9.86yrs; range 33.9-66.11) presenting with chronic coughing underwent simultaneous a Restech and MII/pH recording. A time-interval of 2 minutes was allowed between Restech and MII/pH to be considered simultaneous episodes. The results were statistically tested with the Chi-square test; a p value <0.05 was considered significant. Results: A total of 515 reflux episodes were measured with the MII/pH (acid: 181; weakly acid: 310; weakly alkaline: 24). 180 (35%) of these episodes reached the highest impedance channel (hypo-pharynx). However, 74/180 (41%) of these reflux episodes were not related to a change in pH according to the antimony electrode of the MII/pH catheter. With the Restech technique, we found 87 reflux episodes; 35 (40%) of these did correlate with swallows (and thus not with reflux) according to the impedance recording, and 39 (45%) were not associated with impedance or pH modification according to MII/pH. Out of all the reflux episodes detected, only 13 (15%)were detected simultaneously with both techniques (2.5 % for impedance versus 15% with Restech; p: 0.0002). Moreover, we found 49 pH-only reflux events at the pH sensor in the hypo-pharynx with the MII/pH; of them, only 3 (6.1%) were correlated in time with Restech detected reflux. Correlation in time (2 minutes time-interval) between cough and reflux events was positive in 5/10 patients for impedance (symptom index 5/10, symptom association probability 4/10). Correlation in time between cough and reflux was positive in 0/10 patients according to Restech technique. Discussion: Our results show that Restech detected less reflux episodes than impedance; 35% of the reflux events according to Restech were swallows according to impedance. Moreover, time correlation between cough and reflux could not be demonstrated with Restech.