ObjectiveTo evaluate the relation between protein expression of RAS-association domain family 1A (RASSF1A) gene and the occurrence and development of vulvar cancer. MethodsImmunohistochemistry was used to detect the expression of RASSF1A protein in 9 normal vulvar tissues, 12 vulvar intraepithelial neoplasm (VIN) tissues, as well as 35 vulvar cancer tissue samples which were taken from patients treated during January 2008 to December 2010. Then, we analyzed the correlation between the RASSF1A protein expression and the clinical pathological features of vulvar cancer. ResultsThe expression of RASSF1A protein in vulvar cancer samples was significantly different from that in samples of normal vulvar tissues and VIN tissues (P<0.05). Significant difference also existed in the expression of RASSF1A protein between normal vulvar tissues and VIN tissues (P<0.05). The expression of RASSF1A protein was not significantly correlated with age, grade, stage, lymph nodes involvement and sites (lateral/median) of vulvar cancer (P>0.05). ConclusionInactivation of RASSF1A gene involves in the occurrence of vulvar cancer but has no significant correlation with its development. There is no obvious correlation between cancer sites, onset ages and the expression of RASSF1A protein.