This paper proposes a high utility based infrequent weighted item set mining (HUIWIM) approach to address the challenges of mining infrequent item sets with user-defined utility thresholds. The approach improves efficiency by analyzing both item occurrence frequencies and their utility parameters, thereby enabling the discovery of product combinations that are infrequent yet highly profitable. The proposed methods show enhanced performance over existing systems in mining high utility infrequent item sets from transactional databases.