Antimicrobial 
substances have been found in plants because medicinal plants are a rich supply of medications, traditional medicines, and ingredients for drug manufacture.  This study aimed to examine how laser irradiation affected the crude petroleum ether extract made from populus spp. leaves. In this study, crude petroleum extract exposed to laser light was tested in vitro for its ability to inhibit the growth of several fungal species, including Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger, Penicillium brevicompactum, and Penicillium expansum, which were isolated from isolate bank of the Veterinary-Microbiology Laboratory- Hospital in Wasit. Before and after being exposed to laser light, Populus spp. extracts had no antifungal effects on culture using well diffusion techniques. No statistically significant differences were found when comparing the biomass concentration of fungus exposed to light for 30 and 60 minutes with the control group. The GC-MS analysis revealed the existence of additional substances in the crude petroleum ether extracts, whether they had been subjected to laser light or not. Different substances, including Dimethyl methylphosphonate, Propanoic acid, 2-chloro-, 1-methy lbutyl ester 3-Chloropropionic acid, 3-chloropr op-2-enyl ester tetra-n-Propoxymethane, cis-9-Hexadecenoic acid cis-Vaccenic acid,  Propyl tetradecyl carbonate  - Carbonic acid, butyl decyl ester, Carbonic acid, heptadecyl propyl ester  and Hexanedioic acid, bis(2-ethylhexyl) ester. The current study hypothesizes that short-term laser treatment of a crude petroleum ether extract made from Populus spp. leaves causes changes in the plant compounds that can be detected through GC-MS thanks to the radiation's increased energy consumption.