Most red-cotyledon microsperma lentils (Lens culinaris Medikus) are utilised after postharvest processing into split dehulled seed. This study examined the effects on dehulling of 23 diverse genotypes of red-cotyledon microsperma lentil, each grown at three sites ranging from 245 to 663 mm total seasonal rainfall in Lebanon and Syria. Dehulling efficiency (%) was measured as the sum of split dehulled seed, whole dehulled seed, and whole hulled seed. Despite a range in location means of 464-2018 kg ha-1 for grain yield, the corresponding mean dehulling efficiencies varied only from 84.8 to 85.9%, indicating that the location effect on dehulling efficiency is of minor importance. There was more variation among genotypes for dehulling efficiency (80.8-87.7%) and for preparation of split dehulled seed (62.1-80.2%) than between locations. Seed processing variables showed medium to high broadsense heritabilities. Correlations between seed processing characters and agronomic variables were generally low. An approach to seed selection for optimum processing variables within the ICARDA breeding programme is discussed.