In this work we quantified various growth factors in the myocardium of 19 patients with chronic chagasic cardiomyopathy and heart failure, through the immunoperoxidase technique. We looked for T. cruzi antigens, growth factors (GM-CSF, TGF-beta1, PDGF-A and PDGF-B) and inflammatory cells (CD4+, CD8+, CD20+ and CD68+). The mean ratio of CD4+/CD8+ T lymphocytes was 0.6 +/- 0.3. The mean number of positive interstitial cells was 5.9 +/- 3.1 for CD68+ (macrophages); 7.5 +/- 4.3 for PDGF-A+; 2.9 +/- 2.7 for PDGF-B+, 2.2 +/- 1.9 for TGF-beta1+ and 2.3 +/- 1.9 for GM-CSF+. The immunoreaction for PDGF-A was intense, occurring also in the endothelium, smooth muscle cells and the sarcolemma; there was no correlation between the number of positive interstitial cells and the semiquantitation of the same growth factors in the other cells. TGF-beta1 presented low expression in 100% of the cases. In conclusion, PDGF-A and B are probably the growth factors most related to the proliferative lesions and fibrosis present in chronic chagasic cardiomyopathy. GM-CSF and TGF-beta1 are present in low levels. There was no statistical correlation between growth factors and the quantity of the parasitic antigens.