Abstract Background Doxorubicin (DOX)-based chemotherapy for Hodgkin lymphoma (HL) yields excellent disease-free survival, but poses a substantial risk of subsequent left ventricular (LV) dysfunction and heart failure, typically with delayed onset. At the cellular level, this cardiotoxicity includes deranged cardiac glucose metabolism. Methods By reviewing the hospital records from January 2008 through December 2016, we selected HL patients meeting the following criteria: ≥ 18 year-old; first-line DOX-containing chemotherapy; no diabetes and apparent cardiovascular disease; 18-fluoro-deoxyglucose positron emission tomography (18FDG-PET) scans before treatment (PETSTAGING), after 2 cycles (PETINTERIM) and at the end of treatment (PETEOT); at least one echocardiography ≥ 6 months after chemotherapy completion (ECHOPOST). We then evaluated the changes in LV 18FDG standardized uptake values (SUV) during the course of DOX therapy, and the relationship between LV-SUV and LV ejection fraction (LVEF), as calculated from the LV diameters in the echocardiography reports with the Teicholz formula. Results Forty-three patients (35 ± 13 year-old, 58% males) were included in the study, with 26 (60%) also having a baseline echocardiography available (ECHOPRE). LV-SUV gradually increased from PETSTAGING (log-transformed mean 0.20 ± 0.27) to PETINTERIM (0.27 ± 0.35) to PETEOT (0.30 ± 0.41; P for trend < 0.001). ECHOPOST was performed 22 ± 17 months after DOX chemotherapy. Mean LVEF was normal (68.8 ± 10.3%) and only three subjects (7%) faced a drop below the upper normal limit of 53%. However, when patients were categorized by median LV-SUV, LVEF at ECHOPOST resulted significantly lower in those with LV-SUV above than below the median value at both PETINTERIM (65.5 ± 11.8% vs. 71.9 ± 7.8%, P = 0.04) and PETEOT (65.6 ± 12.2% vs. 72.2 ± 7.0%, P = 0.04). This was also the case when only patients with ECHOPRE and ECHOPOST were considered (LVEF at ECHOPOST 64.7 ± 8.9% vs. 73.4 ± 7.6%, P = 0.01 and 64.6 ± 9.3% vs. 73.5 ± 7.0%, P = 0.01 for those with LV-SUV above vs. below the median at PETINTERIM and PETEOT, respectively). Furthermore, the difference between LVEF at ECHOPRE and ECHOPOST was inversely correlated with LV-SUV at PETEOT (P < 0.01, R2 = − 0.30). Conclusions DOX-containing chemotherapy causes an increase in cardiac 18FDG uptake, which is associated with a decline in LVEF. Future studies are warranted to understand the molecular basis and the potential clinical implications of this observation.