The influence of inflammation on the motility of the human gallbladder was investigated through an in-vitro experiment. Motility of longitudinally cut strips from 50 patients were examined by the same method as described in our previous articles. We pathohistologically classified the severity of the inflammation of the specimens into four grades: grade 0 is normal, grade I, slightly inflamed; grade II, moderately inflamed; grade III, highly inflamed. Relationships between the grade of inflammation and the motility of the strips were summarized as follows. 1) In grade 0 cases, the strongest tonic contractions were observed in the strips from the fundus. This tendency was also found in cases of grade I and II but III inflammation. 2) The tonic contractions of the strips from the fundus or body decreased along with the grade of the inflammation. 3) In any strips, the frequency of the rhythmic contractions decreased progressively with the grade of the inflammation. 4) The amplitudes of rhythmic contractions of the strips with grade I and II inflammation were larger than those of grade 0 inflammation.