Hypertrophic cardiomyopathy (HCM) is the most common cardiac disease diagnosed in cats. The clinical presentation in cats varies from an incidental finding on physical examination, such as heart murmur or arrhythmia, to an acute onset of congestive heart failure or sudden death. The aim of this study was to evaluate the clinical profile from domestic cats with HCM from Botucatu city, São Paulo state, Brazil. Twenty-one cats with HCM, diagnosed through clinical signs, physical examination, and imaging tests (radiography and echocardiography) were included in the study. Of the 21 cats examined, 81% were males and 19% were females. The average age was 10.1±4.2. Forty-three percent of the cats was from mixed breed, 43% Persian, 9% Siamese, and 5% was from exotic shorthair breed. The most common clinical sign was thromboembolism in seven cats (33%). Dyspnea was observed in 29% of the cats, cough in 24%, lethargy in 19%, pleural effusion in 14%, ascites in 10%, and cyanosis in 5% of cases. Cardiac arrhythmia (ventricular tachycardia) was observed in only one cat (5%). Azotemia was reported in seven of 21 cats (33%). Arterial hypertension occurred in one cat (5%). In cats with HCM, prophylactic therapy to prevent thromboembolism (the major complication of the disease) is important. Early diagnosis may increase survival of these animals.