Objective The present study aimed to perform a qualitative study of the factors affecting relapse to drug abuse and addiction with a grounded theory approach. Method The method of the current research was the grounded theory qualitative method. The statistical population of the current study included all individuals referring to an addiction treatment clinic in the city of Qorveh in 2020 who had an abstinence period for at least 4 months after a period of drug use, but relapsed again. Among them, 17 people were selected by purposeful sampling method and subjected to semi-structured interviews. In order to facilitate the coding and analysis process, MAXQDA software was used. Results Factors affecting relapse to drug abuse and addiction were identified and extracted, which include: a) underlying factors, including individual, psychological, and interpersonal factors,b) revealing factors, including family factors,c) sustainable factors, including social, cultural, and environmental factors,and d) aggravating factors, including therapeutic factors. Conclusion Several factors play a role in relapse to drug abuse and addiction, which by identifying these factors in different environments, cultures, and societies, preventive measures can be established and developed and public awareness can be created.