We show the records about diagnosed mycoses in a hospital in Mexico City in two periods of time: from 1967 to 1977 and from 1993 to 1997. In the former 15,429 patients were studied and in the latter, 5,998. Striking differences among frequency, etiological agents and clinical outcome, were observed. The most frequent infections in both lapses were the superficial ones, however the most recent scores showed a notorious increase in opportunistic infections. We diagnosed only one histoplasmosis case during the period from 1993 to 1997. Etiological agents have also changed, dermatophytes frequency like Trichophyton mentagrophytes and T. tonsurans have diminished while T. rubrum increased from 60% to 80% of the whole dermatophytoses cases. Even though Criptococcus neoformans used to be the only agent causing criptococosis, in the most recent report we found that C. laurentii, C. terreus and C. unigutulatus were also isolated. Another important difference was mortality in rhinocerebral mucormicosis: twenty years ago it was fairly 80%, nowadays it has decreased to 20%.