This survey research was conducted to examine the factors affecting ecotourism development in Lavasan-e Kuchak Rural District. The statistical population included the experts of Tourism Organization, Municipality and County Seat of Lavasanat District. The data collection instruments consisted of a questionnaire which included personal and professional traits of the respondents, ecotourism development and seven factors including economy, infrastructure, policymaking, culture, geography and extensional-educational factors affecting ecotourism development. The content validity of the questionnaire was confirmed by a group of experts› opinions and its reliability was also determined by Cronbach›s alpha the value of which was above 0.7 for the main scales, which is acceptable. The data were analyzed using SPSS version 18. The results of Pearson correlation test showed that there was a positive and significant relationship between economic, infrastructural, policymaking, social and extensional-educational factors and ecotourism development in Lavasan-e Kuchak Rural District but there was no significant relationship between cultural, geographical and natural factors and ecotourism development. The results of stepwise regression also indicated that extensional-educational accounted for 63.9% of the variance of ecotourism development variable in Lavasan-e Kuchak Rural District. In this regard, some suggestions were given for ecotourism development in Lavasan.