RATIONALE: Hydatidosis, a larval cestode zoonotic infection caused by Echinococcus granulosus, predominantly affects the liver and lungs. While the disease is well-documented in these common sites, cardiac involvement remains exceedingly rare, with an incidence ranging from 0.02% to 2%. Among the cases of cardiac hydatidosis, cysts located at the apex of the heart are particularly uncommon, accounting for only 5.2% of reported instances. PATIENT CONCERNS: A 43-year-old woman presented to the emergency department with fatigue and dyspnea on exertion. Physical examination was unremarkable, and laboratory tests showed normal hematology and coagulation test results, but positive indirect hemagglutination test for hydatid cyst raised suspicion of infection. DIAGNOSES: Cardiac ultrasound revealed an echo-lucent structure in the left ventricle, consistent with a cystic lesion. Further investigation with computed tomography (CT) scans identified a large 9 cm cardiac cyst at the apex of the left ventricle, a 3 cm cyst in the right lung, and multiple well-circumscribed cystic lesions in the right lobe of the liver. These findings strongly suggested the diagnosis hydatid disease. INTERVENTIONS: The patient underwent surgery to evacuate the apical cardiac cyst liquid and remove its laminated layer. Albendazole was prescribed to prevent recurrence of the cyst and treat smaller cysts located in the liver and right lung. OUTCOMES: The patient recovered well with no evidence of cardiac abnormalities or recurrence during follow-up. LESSONS: Cardiac hydatid disease, though rare, poses serious risks in endemic regions. Echocardiography and CT scans help in diagnosing hydatid cysts, measuring their size, and assessing their location. Surgical intervention is recommended, even in asymptomatic patients, to prevent cyst rupture and potential complications.