Despite growing interest in biomass over the last number of years, bio-energy derived from biomass currently contributes to a very small share of the total Spanish energy market. How individual farmers choose to respond to the opportunities presented by these relatively novel crops has still received scarce attention. In this paper, farmers’intentions towards the adoption of energy crops are analyzed. A survey of 201 farmhouseholds in Southern Spain is explored using a non-parametric approach based on classification tree algorithms. The main outcome of this analysis is that off-farm labour factor affects the adoption of energy crops on farm, together with farm specializations, size of owned land and farmer’s education. While the study confirms the relevance of the main determinants available from the literature, need for further research is emphasised.