Patients with primary systemic amyloidosis that affects the heart have a poor outlook. Cardiac troponins T and I (cTnT, cTnI) are highly specific and sensitive biomarkers of myocardial injury. Values of these troponins provide quantitative information about the disease. We retrospectively assessed 261 patients newly diagnosed as having primary systemic amyloidosis. Median survival for patients with detectable cTnT and cTnI (6 and 8 months, respectively), was worse than that for those with undetectable values (22 and 21 months, respectively). Median and 25th and 75th percentile values for cTnT were 0.024 microg/L, less than 0.01 microg/L, and 0.084 microg/L, and for cTnI were 0.1 microg/L, 0.05 microg/L, and 0.24 microg/L, respectively. After multivariate analysis, cTnT proved a better predictor of survival than cTnI.