Necker cube drawing is a well-known effortless cognitive screening with relatively high sensitivity to more serious cognitive problems. Through its standard procedures(with 1 trial pass or fail) it tends to identify far too many clients with possible cognitive problems when applied in a low functioning exposed clientgroup. The aim of the study was to evaluate whether the Necker pass/fail could increase its usefulness after introducing up to five rehearsal trials whenlooking for clients only with serious and durable cognitive problems (WAIS-IIIPOI score <70). When looking for only serious cognitive problems (POI<70), this  procedure could identify 75% of the clients in need of further investigation and made it possible to reduce clients in need of further investigation by almost the half.