Background: Substance abuse is a major challenge in Egypt due to changing pattern of abuse and its threating to health, social and economic build of the community. Aim of the work: the present work aims to demonstrate the pattern of substance abuse in Assiut governorate. Also to study the liver, kidney functions and electrocardiographic changes among addicted patients admitted to Addiction Management Unit of Neurology and Psychiatry Hospital at Assiut University. Patients and methods: the study was done on 80 male in-patients, who are addicted for at least one year and 41 healthy non-abusers. All Patients fulfilled a questionnaire of drug dependence and were subjected to a thorough clinical examination beside measurement of liver functions, kidney functions, electrocardiogram recordings, and urine toxicological screen. Results: Forty-three patients (53.75%) were 25–35 years of age. Their mean of age was 30.47±6.91 years. Multiple substance abuse represented 57.5% (46 cases) and tramadol was the most commonly abused drug. Tramadol was abused alone in 32.5% (26 cases). The technical school (47.5%) was the most common educational level. Family history of abuse was positive in 47.5% of cases. HCV was positive in 15 (18.75%) of cases, 13 of HCV positives cases used injection for substance abuse. There was no significant association between liver and kidney functions changes and addiction duration. However, a correlation was established between liver functions changes and infective hepatitis. There was a high percentage of ECG abnormalities among abusers (53.75%), those abnormalities were in the form of an inverted T wave in 13 patients (30.23%). Conclusion: This research shows that ECG abnormalities are frequently encountered in substance abusers. The results also point out the risk of hepatic damage due to infective hepatitis in injection drug users. Measures to control the spread of substance abuse should be implemented.