Penicillium chrysogenum has been reported as a potent taxol producer based on quantitative analysis by TLC and HPLC. The biosynthetic potency of taxol has been validated from PCR detection of rate-limiting genes of taxol synthesis such as taxadienesynthase and 10-de-acetylbaccatin III-O-acetyltransferase (DBAT), which catalyzes the immediate diterpenoid precursor of the taxol substance, as detected by PCR. Taxol production by P. chrysogenum was assessed by growing the fungus on dierent media. Potato dextrose broth (PDB) was shown to be the best medium for obtaining the higher amount of taxol (170 g/L). A stepwise optimization of culture conditions necessary for production of higher amounts of taxol was investigated. The substance taxol was produced optimally after 18 d of incubation at 30 C in PDB adjusted initially at pH 8.0 with shaking (120 rpm) (250 g/L). The P. chrysogenum taxol was purified successfully by HPLC. Instrumental analyzes such as Fourier transform infrared spectroscopy (FTIR), ultraviolet (UV) spectroscopy, 1HNMR and 13C NMR approved the structural formula of taxol (C47H51NO14), as constructed by ChemDraw. The P. chrysogenum taxol showed promising anticancer activity.