Industrial pulp and fiber of Eucalyptus and Fagus were investigated for possible identification of secondary metabolites, using chloroform, ethanol and methanol/HCl extracts. The total phenolics test was positive with all the samples and some phenolic compounds like vanillin, vanillic acid and syringic acid were identified by HPLC analysis in the ethanol and methanol-HCl extracts. The extracts had also DPPH radical scavenging activity. Fatty acids like palmitic acid, linoleic acid, oleic acid and stearic acid, cholestane and its derivatives were found in the different extracts by GUMS analysis. Squalene was also identified and quantified by GC/FID in the dichloromethane extracts. The results showed that the industrial pulp and fibers still contain some secondary plant products comparable to those of the original woods, which confirm the 'botanical origin' of the fibers and enables the natural fibers to possess some biological properties, like DPPH antioxidant activity.