Forty-six Streptomyces strains were isolated from paintings and stone surfaces from Tell Basta and Tanis tombs (80km south-east Cairo, Egypt). Eight of these strains were selectec to determine their sensitivity against 13 antibiotics. In general, high levels of resistance could be observed. Gentamycin, spiramycin and doxycycline wer the most effective antibiotics against the majority of strains under study. Due to the observed antibiotic resistances, gamma irradation was studied as a possible alternative to inhibit microbial growth. Isolated bacteria were exposed to different doses of gamma irradation (5, 10, 15, 20 and 25 kGy). The growth of all Streptomyces isolates except S. canarius was completely inhibed at 25 kGy. The applied doses of gamma irradation did not cause any observable alterations or colour changes to pigments and binding media (arabic gum, animal glue and egg-yolk) used in the paintings.