Background:There are many factors which affect nutritional status of addicted such as lack o f knowledge, incorrect attitude toward modification of food pattern, and careless to food intake.Objectives:The aim of this study was to determine the effectiveness of educational program on nutritional behavior in addicts referring to Baharan hospital in Zahedan.Patients and Methods:Thirty-six addict patients were selected randomly. After recording general demographic data of patients, nutritional behaviors were determined. To determine the effectiveness of nutritional educational program, pre and post-tests were performed. Evaluation of nutritional behavior was determined as poor, fair and satisfactory levels. Statically analysis was performed by SPSS software.Results:Most addict patients had a medium level of education. Improvement in knowledge, attitude and practice (KAP) of patients after intervention was observed as follows; decreasing KAP in poor level (2.8% vs. 30.6%), (3% vs. 50%), (25% vs. 80.6%), respectively; also, increasing KAP in fair level (7% vs. 55.6 %), (15% vs. 15%), (19% vs. 7%), respectively and increasing KAP in satisfactory levels (77.8% vs. 13.8%), (50% vs. 8.3%), and (22.2% vs. 0%), respectively (P < 0.0001). There was a significant difference regarding the grade of KAP in patients based on gender, marital status, and education level after education (P < 0.0001).Conclusions:This study showed that nutritional KAP was improved in addicts. After intervention, there was a significant difference in the score of knowledge, attitude, and practice scores in patients in the current study. KAP was improved in patients after intervention including; decreased KAP in poor level and increased KAP in fair and satisfactory levels. This finding indicates that addict patients would like to modify their life style.