We encountered a case of mushroom intoxication complicated by “toxic-like” myocarditis. Because of the lack of systematized knowledge on this subject, we performed a systematic review of the literature on cardiac toxicity in mushroom poisoning (MP). The aim of this study was to identify and describe the severity, the causal relationship, and the mushroom species involved in other reported cardiac events associated with MP. We included 39 studies in our review. We found 106 cases of cardiac events associated with MP, including 18 deaths. A wide variety of cardiac manifestations were reported, ranging from the simple elevation of cardiac enzymes (n = 61) to ventricular tachycardia (n = 14), acute heart failure (n = 18), and myocarditis (n = 7). Causal relationship between cardiac manifestations and mushroom poisoning was assessed for 42 patients, applying the algorithm validated by the French Toxicovigilance Coordination Committee. Twenty-three cases (54.8%) had a “possible” causal relationship, eight cases (19%) a “probable” relationship, and ten cases (23.8%) a “very probable” relationship. Several fungal genera were involved in reported cases, including Amanita but also rarer ones like Russula and Tricholoma. In conclusion, we showed that cases of cardiac toxicity following MP have been documented in the existing literature, and for some of them, we assessed a strong causal relationship.