Novelties in systems of sexing and marking less dimorphic species of gekkonid lizards are described and first results are presented on the Moorish gecko, Tarentola mauritanica, used as target and model species. Inspection of cloacal opening and tail basis to detect hemipenes has been done with a small probe and with laser light. Behavioural response to tail basis touch was typical of adult males. Permanent marking has been performed along with the removal of some subdigital scales. Sexing was suitable and feasible on all individuals larger than 45 mm snout to vent length.