This study reports an association of behavioural and morphological directional asymmetries at the level of individual lizards. I counted all subdigital lamellae (scales) under the toes of 57 Hoplodactylus duvaucelii on North Brother Island, New Zealand. Geckos released first from the substrate the hindlimb that had fewer subdigital lamellae than the other hindlimb. Analyses of data from the literature show that in geckos, clinging ability increases with the number of subdigital lamellae, especially after variation in body mass is accounted for. Assuming that grasping (an active process) and clinging (a passive process) abilities are correlated, the association of behavioural and morphological asymmetry among individuals could be interpreted in functional terms: geckos lift first from the substrate the hindlimb that has the lowest ability to stick to the substrate.