Background In 2019, 600’000 people in Africa died of heart failure and heart diseases will increase on the continent. It is crucial to understand the regional etiologies and risk factors for heart failure and underlying heart diseases. However, echocardiography data from rural Africa are scarce and from Lesotho non-existent. This study aims to examine the occurrence, characteristics and etiology of heart failure and heart diseases using echocardiography data from a referral hospital in rural Lesotho. Methods We conducted a retrospective cohort study at Seboche Mission Hospital, the only referral hospital in Butha-Buthe district (Lesotho) with an echocardiography department. We included data from all individuals referred to the department between January 2020 and May 2021. From non-hospitalized patients echocardiographic diagnosis, sex and age were available, from hospitalized patients additional sociodemographic and clinical data could be extracted. Results In the study period, a total of 352 echocardiograms were conducted; 213 had abnormal findings (among them 3 children). The majority of adult participants (130/210; 64%) were female and most frequent heart diseases were hypertensive (62/210, 30%), valvular (39/210, 19%) and chronic pulmonary (37/210, 18%). Heart failure represented 11% of hospitalizations in the same period. Among the 126 hospitalized heart failure patients, the most common etiology was chronic pulmonary heart disease (32/126; 25%). Former mine workers and people with a history of tuberculosis were more likely to have a chronic pulmonary heart disease. Conclusions The leading cause of heart disease in this setting is hypertension. However, in contrast to other African epidemiological studies, chronic pulmonary heart disease is unexpectedly common. There is an urgent need to improve awareness and knowledge about lung diseases, make diagnostic and therapeutic options available and increase prevention.