Leaf and (unripe and ripe) berry essential oils of Juniperus oxycedrus ssp. badia (H. Gay) Debeaux grown wild in Spain have been analysed by capillary GC and GC-MS in combination with retention indices. A seasonal investigation of both leaf and berry oils was also performed. Among the approximately 80 constituents investigated (representing 90-98% of the oils) 60-68 were identified (80-97% of the oil composition). The leaf oils were mainly composed of alpha-pinene (40-57%) and manoyl oxide (5-10%). The (unripe) berry oils were dominated by alpha-pinene (65%) with moderate amounts of myrcene, limonene, germacrene D or gamma-muurolene. Several differences in yields and chemical composition from a qualitative and quantitative point of view were detected when comparing all the oil samples analysed. In addition, two oil samples were examined, but found inactive, against the replication of HIV-1(III(B)) and HIV-2(ROD) in cell culture, whereas the samples were toxic for the cells at a 50% cytotoxic concentration of 106 and 123 microg/ml, respectively.