A systematic study of the distribution of intracellular parasites in the organs and tissues of mice acutely infected (15 days) with the CL strain ofTrypanosoma cruziwas performed. Almost all tissues and organs were parasitized with different intensities, including several epithelial cell types. In addition to striated, cardiac, and smooth muscles a very high parasitism of fat cells, pancreas, and genital adnexa was observed. A smaller number of parasites was found in all other structures studied except in highly vascularized structures such as in the penile corpora cavernosa, pulmonary and renal parenchyma, islets of Langerhans, hepatic sinusoids, and in atrial endothelium. This paper also shows, for the first time in the literature, the parasitism of milky spots, cornea epithelium, cornea stroma, retroorbital fibroblasts, seminal vesicles, and coagulative, Cowper's, urethral, preputial, sebaceous anal, and clitoris glands. The results indicated that CL strain is highly invasive, being able to infect cells derived from the three embryonic layers (ectoderm, mesoderm, and endoderm), suggesting that the paninfectivity may influence the outcome of immunological and pathological events.