Results of a normative and reliability study on the Tower of Londona-Drexel (TOLDX), a test of planning, are reported for a sample of 385 Turkish adults from five age groups: 16-19, 20-29, 30-39, 40-59, and 60+ age groups. The study examined the influence of age, gender and education on the test performance. Mean performance and percentile ranks are presented for the five age groups. The results showed a significant age effect, which was mainly due to the 60+ age group performance. The performance of 60+ age group was significantly poorer than those of the other four groups. There were no major changes in performance from 16 to 59 years-old., The study also revealed that there were essentially no differences between females and males in all the TOL scores, except for the Total Rule Violations and the Total Execution Time. Education level had a marked influence on the TOLDX performance. Overall the high education group performance was better than the middle and the low education groups. The TOLDX also demonstrated, good test-retest reliability coefficients, ranging from a low of. 45 to a high of. 74.