This study attempts to identify the cause of lowing rate of irrigation use fee's collection through the examination of the farmer affordability in paying the fee. The study chooses to investigate one of the nine pilot irrigation management transfer programs in the Lao PDR. The study scheme, Ban Vuen-Tonhen water user association, has earned remarkable reputation in outstanding operation and management, water distribution, and the fee collection. The irrigation service fee (ISF) affordable function and 45 degree plotting diagram are used in the analysis. The findings indicate that farmers, who cultivate rice only, have the least capacity to pay the fee. However, other farmers, who cultivate rice and cash crops or only cash-crop, are able to pay the fee and 11 times higher than current ISF charged. The study also confirms that ISF paid farmers actually line closely to the total average ISF. Finally, the role of commercialized farming has played a critical role in enhancing the payment and farmer affordability.