In previous studies, N,O-carboxymethyl chitosan has been shown to decrease the incidence and intensity of abdominal adhesions. In the present study, adhesions were induced in 220 rabbits using a double uterine horn model. Rabbits were randomized to receive an operation only or an operation+medical chitosan intraperitoneally. Twenty-two rabbits from each group were euthanized at one of five different times (Day 3, 7, 14, 28, or 42), and adhesion formation was given gross and histopathological scores. Reductions were observed in adhesion extent (P=0.0337) and tenacity (P=0.0271) as well as inflammation (P<0.0001) on Day 3 when medical chitosan was applied. Prior to Day 14, fibrosis was less obvious in the medical chitosan group (P< 0.0005). The tenacity scores were significantly lower in the medical chitosan group following Day 14 (P<.05), while the type scores were lower in the medical chitosan group following Day 28 (P<.03). Thus, medical chitosan decreased both the gross and the histopathological scores of the induced adhesions.