The cephalic extract of Australian colletid bee, Hylaeus albonitens, comprises 10 components: linalool, citronellal, neral, geranial, nerolic acid, geranic acid, heptadecane, pentacosane, Z,Z‐ and E,E‐9,12‐octadecadienoic acid. Quantification of these major components suggested it to be an aggregation pheromone composition. The fairly large amounts of 9,12‐octadecadienoic acids have not been reported before in the cephalic extract of bees. The chromatographic pattern is quite different from the previous reports on the constituents of mandibular glands of American Hylaeus modestus and the related European and North American Colletes bees.