The study was carried out to determine the contributions of agricultural extension workers in promoting sustainable agricultural development among farmers in Kaduna State, Nigeria. Six specific objectives were raised. Descriptive survey research design was adopted. The population of farmers in the three senatorial districts were 4,056 and sample size of 333, were randomly selected. Structured questionnaire were used to collect data. Analysis of Variance (ANOVA) was used to determine the responses of farmers. The result reveals that 59.5 percent of the respondents are between the ages of 20 to 34 years, about 58% of farmers are male, and less than 70% are married. Majority of the farmers are educated (75%). Agricultural Extension Workers contributed through the control of erosion in the farm land, that farmers were influenced by Agricultural Extension Workers by disinfecting their store houses against pest and diseases before storage with 67% of the respondents agreed to the statement.