Agriculture is an important sector of Zambia’s economy, serving as the main source of income for the rural population. Its production is mainly dependent on rain-fed hoe cultivation and maize remains an important staple food crop. In order to improve food security, generate income and minimize risks associated with heavy dependence on maize, the government of Zambia has been promoting crop diversification. This study was carried out with the objectives of : i) to determine the extent of crop diversification, ii) to compare the demographic and socio-economic characteristics of diversifiers and non-diversifiers, and iii) to identify the major determinants that influence farmer’s decisions to diversify in crop production. The Crop diversification index (CDI) was used to measure the extent of diversification while the Tobit model was used to analyze the determinants of diversification. Bivariate statistical analysis and mean comparisons were used to compare socio-economic characteristics of diversifiers against their non-diversifying counterparts. The extent of crop diversification among the smallholder farmers was relatively low since the majority of the diversifiers had a lower CDI value; 42.35% had a CDI greater than zero but less than or equal to 0.49; 5.87% had a CDI equal to 0.5 and 20.78% had a CDI greater than 0.5. On the other hand, the non-diversifiers constituted 31% of the total sample. The size of landholding, quantities of fertilizer, distance to the market, tillage time and tillage (using a plough) were found to significantly determine crop diversification. vii Based on the study findings, the following recommendations were drawn; the need for the government to undertake policies that will improve farmers’ access to and control over land, encouraging farmers to use agricultural implements such as ploughs and supporting policies oriented towards bringing trading markets closer to the farmers.