There is overwhelming evidence that smallholder cropping systems in Sri Lanka are strongly influenced by major socio-economic factors together with the biophysical environment. The overall aim of this study was to determine how market accessibility, crop profitability, labour and land availability influence decision making, success or failure and distribution of smallholder cropping systems. Ethnographic techniques were employed for the data collection in four selected villages of the Wet (Kobawaka and Pannila) and Intermediate (Pallekiruwa and Bookandayaya) Zones. A marketing study was undertaken in two markets (Parakaduwa and Medagama). Population studies were undertaken by involving village-level officers and key informants in each village, and a stratified random sampling method was applied in order to derive a representative sample within the village. A sample of 24 households from each village including at least three households with each major cropping system (permanent, semi-permanent, seasonal and homegarden crops), was selected. Data were analysed using a variety of statistical methods including chi-square, general linear model (GLM) and discounting. The overall findings were that selection of cropping systems depended on socio-economic background and market accessibility of the villages along with the land, labour and income availability of households. In particular, the amount of land allocated for banana (Musa spp.) monocropping was significantly determined by the market accessibility, low costs of production, level of flexibility in labour use and land availability, resulting in more banana monocropping in the Intermediate Zone than in the Wet Zone. Costs of production, particularly establishment costs had a large influence on selection of crops. Rubber (Hevea brasiliensis) and arecanut (Areca catechu) were cultivated by a large number of low-income farmers, despite the fact that tea (Camellia sinensis) and pepper (Piper nigrum) restricted to high-income farmers because of their high establishment costs, provided higher overall profits. The type of labour (family, hired, shared or a mixture of these) used at household level was greatly influenced by education and occupation of the head of the household. In remote villages, where families were well connected and the majority of relatives lived in close proximity, problems associated with labour were overcome using the shared labour system. The amount, skill and gender division of labour in the households had a considerable effect on which crops were grown and their performance. A decrease in amount of family labour resulted in a decrease in the level of weeding and the survival rate of banana plants, whilst the level of farmer knowledge caused by long-term experience in cultivation and the quality of the extension services influenced the survival rate of rubber. Land size, the form of land ownership, its proximity to the homestead and its quality were strong driving forces in terms of which cropping systems were adopted by farmers. A decrease in land size resulted in an increase in the number of crops grown in homegardens and rubber smallholdings. Crop selection was strongly related to proximity of land to the homestead, consequently crops with less risk and maintenance were grown further out ( e.g. citronella ( Citronella cymboponun) and rubber compared to banana and tea). Similarly, the form of land ownership influenced crop selections and level of maintenance. Privately owned rubber smallholdings consisted of a mixture of intercrops (including some other permanent crops), and soil protection methods were practised, whereas tenanted farms had seasonal intercrops and less attention to soil protection and improvement. However, all these associations were modified by the availability of alternative income sources in a particular household. The results confirmed that market, labour and land have overriding effects on smallholder cropping systems in Sri Lanka. Lack of extension services for rubber and the need for improved road and transport networks were identified as critical in the Intermediate Zone while lack of a well-connected market for banana, and increasingly acute labour shortages for harvesting tea and rubber were critical in the Wet Zone. The implications of these constraints in the context of policy making in the agricultural development of Sri Lanka are discussed and priorities for further research are suggested.