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Designing of new antimicrobial drugs is always needed to solve the problem of continue resistance emerging among microorganisms against antibiotics already in use. Microorganisms from unusual environments, such as reported from the surface and inside of rocks are a repository of certain metabolites that might be able to solve the problem of increasing resistance against antibiotics. The present study was designed to isolate endolithic and epilithic bacterial strains from the rapidly weathering rocks collected from Nathiagali, Pakistan to characterize and screen them for antimicrobial activity. The isolates were identified based on 16S rRNA sequence analysis. Antibacterial activity of the isolates was checked against ATCC strains E. coli, Staphylococcus aureus, and Pseudomonas aeruginosa. Seven different types of antibiotic discs were used to check the intrinsic resistance of all the isolates to various antibiotics. Interestingly, most of the isolates were found resistant while only a few were susceptible, however, the isolates Lysinibacillus spp. N40 and Brevundomonas spp. P20 showed no activity at all. Increased levels of resistance to heavy metals such as; iron, arsenic, cadmium, chromium, and nickel were shown by strains like; Alcaligenes spp. N14 and N21, Bordetella spp. N30 and Streptomyces spp. N28. Alcaligenes spp. N27 and Lysinibacillus spp. P17 showed strong activity against all the three ATCC strains. The study concludes that the bacteria isolated from the rocks having substantial resistance to heavy metals are also showing good antibacterial activity as well as, and they are also potential candidates for the applications in pharmaceutical as well as environmental research. [ABSTRACT FROM AUTHOR]