This study analyzed the determinants of the productivity of smallholder arable crop farmers with a particular focus on land fragmentation using the Simpson Index as measures of land fragmentation in Imo state of Nigeria. Data collected by using structured questionnaire and interview schedules were analyzed using simple descriptive statistics; Simpson index and regression analysis. Results showed that a greater percentage of the respondents were females, while the average age of the respondents was 52 years. About 90% of the respondents had formal education. The average farm size cultivated by the respondents was about 1 ha. Farming was the primary occupation of majority (73.33%) of the respondents. About 63.33% of the respondents were not visited by extension agents during the last cropping season. The Simpson index was 71.91%, indicating high degree of land fragmentation. The significant factors influencing the productivity of the farm were fragmentation, fertilizer, labour, and planting materials. Land reform policies and programmes that would give farmers access to more contiguous land holdings for increased agricultural production was recommended. Manuscript profile