This study involves the application of a random-effects double-hurdle model to survey data to identify the farm-level factors affecting the adoption and intensity of herbicide use in rice production in the Philippines. Results broadly indicate apparent differences in the degree to which important explanatory variables affect the intensity and adoption decisions. The age of the farmer, household size, and irrigation are the significant predictors influencing the decision of farmers to use herbicides, while economic variables such as the price of herbicides, total income of farmers, and the use of bank loans or credit are the highly significant factors determining the intensity of herbicide use. Significant determinants of both the adoption and intensity decisions are land ownership, farm area, and the method of crop establishment used. Results suggest that all of the identified significant predictors in both herbicide use decisions can be considered by the national government when designing policies to reduce excessive use of herbicides or to encourage the adoption of alternative methods of weed control. This is important because for small rice producers, like the majority of Filipino farmers, improved weed management techniques that build on their traditional practices and that are compatible with their resources will be more easily adopted by farmers, relative to those that require radical change to the entire farming system.