Objective: To test the hypothesis that a systematic cognitive training with the Categorization Program (CP) will improve categorization abilities and neuropsychologic performance in normal older adults. Design: Before-after between group comparison. Setting: Standard Clinical Setting. Participants: Group 1 was the older adult group (n = 14) and group 2 the younger adults (n = 15). Average age and years of education was 67.285±10.469 and 14.107±2.321 for older and 29.69 years±10.87 and 14.38 years±1.927 for younger adults. Intervention: Subjects received 3–4 hours of cognitive treatment per week for 10–12 weeks. Main Outcome Measures: Two categorization tests (CP Test 1 and CP Test 2) and 3 probe tasks (to check generalization of skills) were constructed for the CP along with extensive neuropsychologic battery. Results: There was no difference between groups in the pretest administration on the CP Test 1. MANOVA analyses demonstrated significant improvement in CP Test 1 (P=.0001) for both groups. Younger subjects demonstrated greater gains than older subjects (P=.002). Both groups scored improved on CP Test 2 at posttest (P=.027). Subjects also demonstrated gains in their probe tasks across time (P=.049). The performance of older subjects approximated the baseline performance of younger subjects after CP training. Conclusions: Normal aging affects certain aspects of categorization performance. The CP is an effective tool to train categorization skills in normal older adults. Future research should expand the subject population to include a larger number of participants. In addition, the inclusion of patients with mild cognitive impairment (MCI) may be another fruitful line of investigation.