Crop diversification is believed to be essential for reducing risk. This study investigated the extent and determinant factors that affect farmers’ decision for crop diversification in Kutaber District characterized by diverse agro-climatic zones in south Wollo zone Amhara Region, Ethiopia. A mixed approach research design was applied. The survey data were collected from Household Surveys, focus group discussion, key informant interviews and personal observation. From the total of households in the area, 194 sample households were selected randomly through multi-stage sampling techniques. The Herfindahl index was used to measure the extent of crops among three agro-climatic zones. Tobit model is used to predict determinant factors of crop diversification in the district. The data revealed that farmers in the study area allocated farmland about 71.38% for cereals, 14.62% for vegetables; 7% for pulses; 6% for oilseeds and 1% for fruit crops during crop production season of the study period. The average number of crops grown was 6, 4, and 3 in Woina-dega, Kolla and Dega respectively. Households that participate in crop production 59.2% and 40.7% were diversified and non-diversified, respectively; however, 28.7, 53, and 18.3 % were diversified in Dega, Woina-dega, and Kolla agro-climatic zones respectively. The results also revealed that gender of household, educational status, Agro-climatic zones, cultivated land, farm plot, credit access, farming experience, extension service, access to irrigation and total livestock owenrship were positively and significantly associated with crop diversification index. Therefore in all cases, the higher crop diversification practice located in Woina-dega Agro-climatic zones. The district government should provide regular extension services to risky area (Kolla), enhance the supply of inputs and subsidies from local governments and other stakeholders, and encourage farmers who attend agricultural training.