Four cases of congenital viral disease are presented. Two cases were of chickenpox (a 2-day old infant and a macerated abortion) and two were of so-called alastrim, which is probably mitigated smallpox (macerated abortions). In all of them one special type of lesion was present: focal, irregularly sized areas of necrosis, with calcium deposits in the central part, sharply demarcated from the surrounding normal parenchyma and accompanied by slight or absent peripheral inflammatory reaction. In Case 1 (an infant who lived 2 days) such lesions were disseminated to all the viscera, especially the brain; the microscopic aspect was like that of congenital toxoplasmosis, and the microscopic examination revealed an essentially necrotizing inflammatory process with extensive calcification and glial reaction. The placenta, examined in two cases of alastrim and one of chickenpox, exhibited similar lesions both on gross and microscopic examination. On the surface and on the cut section there were numerous minute, irregularly spread yellowish areas. The histology showed the presence of tuberculoid-type granulomatous lesions in the villi and extensive areas of necrosis, the intervillous space being occupied by necrotic material and cellular debris. In one of the cases of alastrim (Case 3), there was predominance of the granulomatous lesions; in the other (Case 4), necrosis predominated; in Case 2, of chickenpox, beside the granulomatous lesions, there was extensive necrosis. In the decidual cells there were characteristic inclusions of both the virus diseases. Such placental lesions apparently have not previously been described.