The objective of this paper is to improve the understanding of attribute non-attendance (ANA) in a choice experiment (CE) investigating farmers’ WTA for participating in agri-environmental schemes in southern Spain. Evidence is found of ANA behaviour for both stated and inferred approaches, with models accounting for ANA clearly outperforming those that do not account for it; however, we produce no conclusive results as to which ANA approach is best. In addition, we investigate sources of observed heterogeneity related to ANA behaviour, our results hinting at a positive relationship between ease of scheme adoption and non-attendance to attributes.