Little is known about the effect of nonsteroidal anti-inflammatory drugs (NSAIDs), thiazolidinediones (TZDs), nifedipine and nondihydropyridine calcium channel blockers (CCBs) usage on the risk of all-cause hospitalization among seniors with heart failure (HF). We assessed the risk of all-cause hospitalization associated with exposure to each of these drug classes, in a population of seniors with HF.Using the Quebec provincial databases, we conducted a nested case-control study in a population of individuals aged ≥65 with a first HF diagnosis between 2000 and 2009. Patients were considered users of a potentially inappropriate drug class if their date of hospital admission occurred in the interval between the date of the last drug claim and the end date of its days’ supply. The risks of hospitalization were estimated using multivariate conditional logistic regression.Of the 128,853 individuals included in the study population, 101,273 (78.6%) were hospitalized. When compared to nonusers, users of NSAIDs (adjusted odds ratio: 1.16; 95% confidence interval: 1.13–1.20), TZD (1.09; 1.04–1.14), and CCBs (1.03; 1.01–1.05) had an increased risk of all-cause hospitalization, but not the users of nifedipine (1.00; 0.97–1.03).Seniors with HF exposed to a potentially inappropriate drug class are at increased risk of worse health outcomes. Treatment alternatives should be considered, as they are available.