Abstract Aims This study aims to explore the cardiovascular effects of long-term anabolic–androgenic steroid (AAS) use in both current and former weightlifting AAS users and estimate the occurrence of severe reduced myocardial function and the impact of duration and amount of AAS. Methods and results In this cross-sectional study, 101 weightlifting AAS users with at least 1 year cumulative AAS use (mean 11 ± 7 accumulated years of AAS use) were compared with 71 non-using weightlifting controls (WLC) using clinical data and echocardiography. Sixty-nine were current, 30 former (>1 year since quitted), and 2 AAS users were not available for this classification. Anabolic–androgenic users had higher left ventricular mass index (LVMI) (106 ± 26 vs. 80 ± 15 g/m2, P < 0.001), worse left ventricular ejection fraction (LVEF) (49 ±7 vs. 59 ± 5%, P < 0.001) and right ventricular global longitudinal strain (−17.3 ± 3.5 vs. −22.8 ± 2.0%, P < 0.001), and higher systolic blood pressure (141 ± 17 vs. 133 ± 11 mmHg, P < 0.001) compared with WLC. In current users, accumulated duration of AAS use was 12 ± 7 years and in former 9 ± 6 years (quitted 6 ± 6 years earlier). Compared with WLC, LVMI and LVEF were pathological in current and former users (P < 0.05) with equal distribution of severely reduced myocardial function (LVEF ≤40%) (11 vs. 10%, not significant (NS)). In current users, estimated lifetime AAS dose correlated with reduced LVEF and LVGLS, P < 0.05, but not with LVMI, P = 0.12. Regression analyses of the total population showed that the strongest determinant of reduced LVEF was not coexisting strength training or hypertension but history of AAS use (β −0.53, P < 0.001). Conclusion Long-term AAS users showed severely biventricular cardiomyopathy. The reduced systolic function was also found upon discontinued use.