INTERPAKS, Examines the level of significance of extension services and the marginal contribution of extension services to increased agricultural production in Gujarat State (1976-77). In addition, the marginal contributions of extension services are compared for the high and low productivity areas of the state. Results of the regression analysis indicate that extension investment has played a significant role in increasing agricultural production only in the high productivity areas while in the low productivity areas it has played an insignificant and even negative role.