The composition of the essential oils of nine populations of Cistus parviflorus L., from Crete (Greece) and their interpopulation variability, were investigated by GC-MS. 114 compounds were identified representing an average of 85–96% of oil composition. Labdane diterpenes were detected and identified in the essential oils of Cistus parviflorus L. for the first time. The results obtained from GC-MS analysis of the volatile oils were submitted to principal component and chemometric cluster analysis. Two main chemotypes (clusters) were differentiated; the first of West Crete and the second of East Crete. Carvacrol, caryophyllene oxide, α-epi-cadinol, abietatriene, 4-epi-dehydroabietol, dehydro abietol, cis-ferruginol and manoyl oxide mixture of isomers are the main constituents, while oxygenated sesquiterpenes as well as diterpenes have been found in high percentage composition.