The role of iron was evaluated in pigs that died suddenly of microangiopathy (mulberry heart disease) characterized by myocardial and endothelial cell damage and capillary microthrombosis. Myocardial iron concentration (mean ± SD) in pigs with microangiopathy (416 ± 87 µg/g, dry weight) was significantly (p < 0.001) higher than in pigs with other diseases (294 ± 93 µg/g) and in healthy slaughter pigs (231 ± 43 µg/g). Similarly, hepatic iron concentration in pigs with microangiopathy (1,211 ± 254 µg/g) was significantly (p < 0.001) higher than in pigs with other diseases (873 ± 296 µg/g) and in healthy slaughter pigs (831 ± 284 µg/g). The results indicate that myocardial and hepatic iron concentration was increased in pigs with microangiopathy. Increased myocardial and hepatic iron concentration might have promoted oxidative stress in selenium-vitamin E-defïcient pigs and thus contributed to the development of oxidative damage.