The study examined the differential efficacy of Verbal Self-instructional (VSI) training on tribal and non-tribal low achieving school children who follow either internal locus of control (ILC) or external locus of control (ELC} and the maintenance of training effects over time and generalisation across different tasks and settings. Type of sub-culture (Tribal vs. Non-tribal) has been crossed with the type of locus of control (Internal vs. External} to produce four VSI treatment groups with 20 Ss per cell. The treatment groups received two months training and were retested after training for posttest and follow-up data. The VSI training has been very much beneficial to the non-tribal children and those having ILC but failed to yield desirable results for the tribal and children with ELC. The VSI effects were maintained for a period of four months and evidenced clear generalisation effects to a variety of task situations and different settings. The importance of child variables as active moderators of VSI treatment efficacy has been discussed.