Under the notion of environmental-friendly and sustainable development, organic farming is gaining traction worldwide. In Taiwan, farmland allocated to organic farming has grown rapidly, up to 1.37% by 2020. Among different crop categories, rice has taken the largest share during the past two decades. Drawn from the 2015 Agriculture Census data at the township level, this study analyzed the determinants of the adoption rate of organic farming for rice farm households in Taiwan. This study departs from the previous research by considering the socioeconomic characteristics of both farm operators and household working population at average township levels. In addition, two spatial econometric models—spatial lag model and spatial error model—are used to deal with the estimation bias resulting from the spatial autocorrelation of organic adoption rates. The spatial autocorrelation index, Moran’s I, which is estimated from the global spatial autocorrelation analysis, equals to 0.366, indicating that there are spatial clusters in the township adoption rate of organic farming. Results from spatial econometric analyses suggest that, the proportion of major operators at different age groups, educational levels and workday groups are the major determinants of township-level adoption rates. In addition, working-age members’ gender ratio, proportion of different educational levels and portion of non-agricultural workers also explains the variations in organic adoption rate. This study provides essential references for policy design aiming at organic agriculture development in the future, which thus enhances the efficiency of organic agriculture development.