Abstract: The essential oil content and chemical composition of German chamomile (Matricaria chamomilla L.) were determined at different irrigation regimes (irrigation at 100, 85, 70 and 55% of field capacity, respectively). Essential oil was obtained by hydro-distillation of dried flower and was analyzed by GC-MS. Results indicated that the yield of dry flower and essential oil per pot, essential oil percent and its composition vary with irrigation regimes. Highest amount of essential oil percent, yield of dry flower and essential oil per pot were obtained from irrigation at 85% of the field capacity. However, it was not significantly different from irrigation at 70% of field capacity. Lowest amount of essential oil percent were obtained when the plants irrigated with 100 and 55% of field capacity. Minimum yield of dry flower and essential oil per pot were observed when the plants irrigated with 55% of field capacity, but it was not significantly different from irrigation at 100% of field capacity. Major constituents of the essential oil for all irrigation treatments were azulene-7-ethyl-1,4-dimethyl, limonene, bisabolol oxides A and B, bisabolone oxide, trans-β-farnesen and isobornyl isobutyrate<8-isobutyryloxy>.