This review examines the relationship between exogenous sex steroids and cardiovascular events and surrogate markers in trans (transgender) people. Data from trans populations is compared to data from postmenopausal women and hypogonadal men when appropriate. In an age-adjusted comparison with cisgender people, trans people appear to have an increased risk for myocardial infarction and death due to cardiovascular disease. It is uncertain whether hormone therapy in trans people affects their risk of stroke. In studies that followed trans people on hormone therapy, the rates of myocardial infarction and stroke were consistently higher in trans women than trans men. There is strong evidence that estrogen therapy for trans women increases their risk for venous thromboembolism over 5 fold. Extrapolating from studies of hormone therapy in postmenopausal women, transdermal estrogen likely carries a lower risk for venous thromboembolism than oral estrogen. Regarding red blood cells, testosterone therapy increases hemoglobin in trans men, and lowering testosterone in trans women has the opposite effect. Regarding blood pressure, the effects of hormone therapy on systolic blood pressure in trans women are inconsistent, with most studies showing an increase. In trans men, testosterone therapy consistently increases systolic blood pressure and may increase diastolic blood pressure. For lipids, hormone therapy may increase triglycerides in both trans women and men. In trans men, testosterone therapy also may increase LDL-cholesterol and decrease HDL-cholesterol.