Plants have been used as alternative remedy for the treatment of various ailments since ancient times. The present study aimed to evaluate some of the biological activities of the plant Sonchus oleraceus in vitro including the hemolytic and antihemolytic effect. Hydromethanolic 80% and aqueous extracts of the aerial parts of plant were prepared using ultrasound-assisted extraction. Phyto-chemical analysis, hemolytic and anti-hemolytic activity of both extracts of Sonchus oleraceus were assessed. Phyto-chemical screening revealed the presence of tannins, carbohydrates, flavonoids, saponins, and phenolic compounds in both extracts. Hemolytic activity assessment has been conducted, using spectrophotometric method. The extracts had low hemolytic effect towards human erythrocytes in concentration-dependent manner.The extracts showed moderate membrane stabilizing effect against hypotonic-induced hemolysis at concentration range of (250-1000 µg/ml). This study also showed that extracts had potential antioxidant activity through the inhibition of H2O2 induced hemolysis. Both extracts showed remarkable antihemolytic activity against H2O2 induced hemolysis at all tested concentrations. It was concluded that the extracts of S. oleraceus manifest low hemolytic effect, and had antihemolytic activity. However, these effects need to be confirmed using in vivo models.