PurposeThe present study aims at examining the determinants of occupational migration of unskilled labourer from domestic agriculture and their impact on farm business income (FBI) in Assam, India.Design/methodology/approachPrimary data for this study were collected during June–November, 2019 from 224 farm (cultivator) households in two contiguous districts in central Brahmaputra valley of Assam. The study used three-stage least square (3SLS) estimation technique for jointly determining the factors influencing migration and remittances and their impact on FBI.FindingsThe result of this study confirms that occupational migration of unskilled labourer from domestic agriculture significantly reduced household FBI. In contrast to the inflow of remittances from migrants helped in increasing the FBI. The migration in the study area considerably influenced by household size, total value of assets holding, networking influence, distance to commercial bank and flood proneness of the village; while the number of migrants, number of dependents and age of migrants seen to be strong predictor of inflow of remittances. Findings of present study offer evidence in support of the new economics of labour migration (NELM) theory.Research limitations/implicationsThe study is restricted to a single crop (paddy) and constrained by the collection of longitudinal data with a revisit to the farm household pre and post-migration of the unskilled labourer from household agriculture.Originality/valueThis paper is based on a novel data set that has especially been collected to examine the determinants of occupational migration from agriculture and their impact on the FBI in Assam that has not been studied before.