Objective: To compare heroin users with their age and gender matched relatives as regards non-invasive investigations like chest x-ray, electrocardiography (ECG) and 2D-echocardiography. Study Design: Case control study. Place and Duration of Study: Study was conducted in Lady Reading Hospital, Peshawar from April, 2019 to March, 2020. Material and Methods: Sixty-one heroin users (cases) and their 100 non-substance abuser age and gender matched relatives (controls) were included through non-probability consecutive sampling. Chest x-ray (CXR), 12- lead electrocardiography (ECG) and two-dimensional echocardiography (2D-ECHO) were done of each one and the result was interpreted by respected consultants. The data were analyzed on SPSS version 15. Descriptive statistics of mean and standard deviation (SD) were described for quantitative variables while frequency and percentages for qualitative variables. Independent samples t-test compared quantitative variables while for qualitative variables chi-square test was used. Ninety five percent confidence intervals were calculated for all variables. Results: Statistically significant differences were noted between cases and controls as regards chest X-ray. A total of 10% cases had findings consistent with tuberculosis (TB) as compared to 3% controls (p=0.045). There was however no cardiac abnormality in any study subject. Significant 12-lead ECG findings other than normal were noticed in 12 (19.7%) heroin users as compared to 10 (10%) controls (p=0.083). In 12 lead ECG, the predominant finding was t wave inversion in leads AVF and III. According to 2D-echocardiography (2D-echo) reports, 15 (24.6%) heroin users (cases) and 17 (17%) controls had abnormal findings (p=0.242). We report no vegetations on any cardiac valve. Conclusion: On radiological and cardiac parameters, heroin users are a different population as compared to the non-heroin users. The knowledge about variations on non-invasive investigations not only helps the healthcare workers to optimize treatment regarding rehabilitation but also facilitate diagnosis and treatment. Keywords: Chest x-ray (CXR), Electro cardiogram (ECG), Heroin addiction, Pulmonary arterial hypertension (PAP), Tricuspid regurgitation (TR), 2D-echocardiography (2D-echo).