The essential oil of Anethum graveolens L. seeds growing wild in South-western Algeria (Bechar) was obtained by hydrodistillation and investigated by GC and GC/MS.Fifteen compounds were identified, which comprised 98.93% of the total constituents. The main compounds were apiol (32.78%) and carvone (31.04%), followed bylimonene (21.26%); piperitone (6.11%) and α-phellandrene (3.28%)amounted to 94.47% of the oil. The antifungal properties of the selected oil were tested against seven fungi. The results of direct contact method showed that the oil was active against mycelial growth of fungal. All strains were inhibited at minimum inhibitory concentrations (MICs) as from 1/500 v/v, except Aspergillus niger at MIC (1/180 v/v). Alternaria alternata was most sensitive, being inhibited at MIC as weak as 1/6500 v/v. In the other hand, a concentration of 1/370 v/v was sufficient to inhibit the sporulation and spores’ germination.