Eucalyptus camaldulensis fixed seed oil was studied by GC-MS. The oil was also assessed for antimicrobial activity. Twenty nine components were detected by GC-MS analysis. Main constituents are: %), 9,12-octadecadienoic acid methyl ester(39.88%); 9-octadecenoic acid methyl ester(19.10%); Hexadecanoic acid methyl ester(14.99%) ; methyl stearate(9.06%) and tridecanedial (3.38%). antibacterial activity of the oil was evaluated via the diffusion assay against five standard human pathogens(Gram positive: Staphylococcus aureus and Bacillus subtilis; Gram negative : Escherichia coli and Pseudomonasa aeruginosa and the fungus Candida albicans). Eucalyptus camaldulensis oil showed excellent activity against all test microorganisms-except for Bacillus subtilis - in the concentration range: 100-25mg/ml. It also exhibited significant activity against the yeast Candida albicans at 12.5 and 6.25mg/ml. It seems that the oil is a lead for further optimization.