Lawsonia alba (Henna) is widely used in folk medicine for treatment of various skin diseases such as Eczema (atopic dermatitis), boils and sores. The aim of the present study is to determine the antioxidant activity, total phenolics and flavonoids content of extracts from the seeds of Lawsonia alba grown in Algeria and selected from three different regions (Adrar, Biskra, and Ouargla). Total phenolics content ranged from 70.64 ± 0.42 to 87.88 ± 0.15 mg gallic acid equivalents (GAE)/g dry weight, the flavonoids content varied from 0.847 ± 0.00 to 1.10 ± 0.006 mg quercetin equivalents (QE)/ g dry weight. The antioxidant activities of the extracts were evaluated by DPPH and phosphomolybdenum assays. The results showed that all extracts from the seeds of Lawsonia alba seem to be good trappers of radicals, the IC50 values of the extracts ranged between 0.0084 and 0.0099 mg/mL. Total antioxidant capacity of the extracts decreased in the following order: SEA >SEB> SEO.