Abstract Introduction Heart manifestations of Churg–Strauss syndrome (CSS) are varied. In the early stages of the disease, it is difficult to distinguish between lesions that are specific to CSS and those of other etiologies. The aim of our work was to compare the characteristics of patients with heart manifestations linked or not to Churg–Strauss syndrome. Material and methods We recorded all clinical symptoms of patients with CSS hospitalized between 1998 and 2008 in Burgundy, France, and determined the possible relationships between heart symptoms and CSS. Results From a cohort of 31 patients, we found 20 with heart lesions. When heart lesions were present, we noted fewer initial symptoms of digestive disorders ( p < 0.05), lower levels of lung infiltrates and fewer anti-MPO pANCA ( p < 0.05). Heart lesions were linked to CSS in 75% of cases. Their patients were thus younger than those in the other cardiac patients ( p < 0.05), were more likely to have clinical manifestations of heart involvement at diagnosis, were less likely to have lung infiltrates on the X-ray at diagnosis and during flare-ups and less likely to have lung abnormalities on X-rays during flare-ups ( p < 0.05) and higher level of leucocytes and eosinophils at diagnosis. Conclusion Heart lesions directly attributable to CSS are frequent, severe and probably underestimated. A specific physiopathology that is not mediated by ANCA seems to be involved in the genesis of CSS-related heart lesions.