To investigate the expression of vaginal IL-23 and its role in experimental murine vaginal candidiasis and its relationship with infection and immune status, immuno-competent (group A) and immuno-suppressed (group B) murine models of vaginal candidiasis were established in estrogen-treated mice. Non-estrogen-treated mice were used as controls (group C). The level of IL-23 p19 mRNA in murine vaginal tissue was determined by RT-PCR. Significantly increased levels of IL-23p19mRNA were observed on the 4th, the 7th and 14th day after inoculation in immuno-competent group when compared with that in control group (P<0.01, P<0.05). However, significant increase of IL-23 p19mRNA were only observed on the 7th day and the 14th day after inoculatuon in immuno-suppressed groups (P<0.05). On the 4th and 7th day, the levels of IL-23 p19mRNA were significantly increased in immuno-competent group than those in immuno-suppressed group (P <0.05). Local IL-23 may play a role in the pathogenesis of murine vaginal candidiasis and has a protective function during infection. Low vaginal IL-23 level may correlate with the increased susceptibility to Candida albicans in immuno-suppressed group.