The term cryptic miliary tuberculosis designates a particular form of hematogenous tuberculosis in which the usual diagnostic criteria, especially the roentgenographic ones, are lacking. Two cases are reported. Initial clinical manifestations were prolonged fever, poor general condition, low blood pressure, low serum sodium, mild hepatic biological disorders, and myocarditis. No other radiological or biological features, suggestive of tuberculosis were found. In the first patient, the various visceral tuberculous localizations occurred under specific treatment, although the latter was otherwise effective. In the second patient, they were identified by pathological examination. The incidence of these occult forms of tuberculosis, where diagnosis is often established too late, and sometimes only postmortem, is not negligible. This possibility must be borne in mind in severe infectious conditions without obvious etiology, particularly when the following features are present : inadequate secretion of ADH, which often indicates latent encephalitic and meningitic involvement where CSF anomalies may be incomplete or lacking ; leucopenia or pancytopenia ; biological hepatic anomalies ; exceptionally, such as in the two cases described, cardiac involvement. Among diagnostic procedures, liver biopsy is of the utmost importance. Mere diagnostic presumption is sufficient to warrant initiation of antituberculous therapy. This ensures survival and, paradoxically, allows delayed overt clinical manifestations to develop.