Peganum harmala has-been used in traditional medicine, but remains a poisonous plant for humans and animals. This plantis a rich source of β-carboline alkaloids, which constitute the majority of alkaloids of Peganum harmala. The present work investigated in vitro, the hemolytic effect of alkaloids from the seeds of Peganum harmala on erythrocytes ruminant animals. The doses tested (0.22 to7.41mg/ml) showed a hemolytic effect on erythrocytes of goats, cattle and sheep. With the dose 7.41mg/ml, the erythrocytes female goats are the most sensitive with hemolysis rate 43.54% in female’s species. In male animals, erythrocytes sheep were the most sensitive, with a rate of hemolysis 35.80%. Peganum harmala alkaloids are capable of disrupting the permeability of the membranes of red blood cells of ruminants.