Studies over the past three years have shown that internal walls of buildings and houses, whether painted or wallpapered, ceiling boards and glass panels, frequently become infested by molds. Mold growths result in fouling, biodeterioration and discoloration of these substrata. Buildings affected by fungi have yielded 28 identified species. Among them are species of <i>Aspergillus</i>, <i>Cephalosporium</i>, <i>Cladosporium</i>, <i>Cyrvykarua</i>, <i>Fusarium</i>, <i>Penicillium</i>, <i>Pithomyces</i>, <i>Trichoderma</i>, <i>Verticillium</i>, and a number of sterile non-sporing isolates. The most widely occurring genera were <i>Aspergillus</i>, <i>Cladosporium</i> and <i>Penicillium</i>, with the former two very abundant wherever they occurred. The most abundant and most often encountered was <i>Aspergillus fumigatus</i>, followed by <i>Cladosporium cladosporioides</i>, and then <i>Curvularia lunata</i>. <i>Fusarium decemcellulare</i> was abundant on ceiling boards and <i>F. solani</i> on wallpaper. Tests carried out with local commercial antifungal paints showed that most were not resistant to fungal growth. Screening tests on the fungicides commonly used by paint manufacturers showed that only one was completely effective and six moderately effective in inhibiting the growth of the molds.