Maize is one of the most important staple foods that is critical to food security and livelihoods of farmers in sub-Saharan Africa. Although maize is important staple crop for ensuring food security, it cannot ensure nutritional security. To provide and ensure an adequate supply and greater variety of nutritional foods within a farm household, cropping patterns and farming systems must be diversified to include micronutrient-rich vegetables and fruit crops, particularly traditional African species. Vegetables provide nutritional benefits and increase household incomes for smallholders, and are thus an excellent complement to staple crops for addressing food and nutritional security. The objective of this study is to ascertain if an increased diversity of crops in farmers’ fields leads to increased diversified diets or otherwise. This underlying objective is analyzed with a multiple linear regression model from a primary survey of 300 farm households selected from 10 villages in the Babati, Kongwa and Kiteto districts of Tanzania. Results show that farm diversity does not have a positive and significant effect on dietary diversity after controlling for other covariates. However, variables such as households size, level of education, monthly expenditure on food, irrigated area, proportion of vegetables consumed from own household production and control of household income by female decision makers were found to have strong association with dietary diversity.