Cancer is a major health problem and the second leading cause of death in the world. Medicinal plants as alternative medicine thus become the choice of treatment given their therapeutic properties, including in Algeria, where plant based traditional medicine is frequently used to treat several cancers. An Ethnobotanical survey was conducted to identify the most prescribed plants for the treatment of cancer by local herbalists in Setif (north-east Algeria. fifty-two Algerian herbalists were interviewed during period of March/April 2023, herbalists were interviewed using semi-structured questionnaires investigating the herbalist. frequency of citation (FC), frequency of citation relative (FRC) and importance family (FIV) were implemented as quantitative methods to demonstrate the relative importance of a chosen species for the treatment of cancer. 58 medicinal plants belonging to 37 botanical families were used to treat cancer. Basing on the frequency of citation (FC), frequency of citation relative (FRC) and importance family (FIV) the most used medicinal plants for cancer treatment are Ephedra alata (FC :34; RFC =0,653), Aristolochia longa (FC: 32; FRC= 0,615), Berberis vulgaris (FC :26; FRC= 0,5), Nigella sativa (FC :20; FRC=0,384), Saussurea costus (FC: 14; FRC= 0,269). The most importance family cited by informants were Ephedraceae (FIV=0.653), Aristolochiaceae (FIV=0.615), Berberidaceae (FIV=0.5), Ranunculaceae (FIV=0.384), Costaceae (FIV=0.173), Annonaceae (FIV=0.153), Moringaceae (FIV = 0.134), followed by: Asphodelaceae (FIV = 0.096), Apiaceae (FIV = 0.086), Amaranthaceae (FIV = 0.076), Rosaceae (FIV = 0.072), Asteraceae (FIV = 0.065), Zingiberaceae (FIV = 0.052). In addition, leaves of these plants which are used (29.31 %) in the powder form (48.28 %) for the treatment of Cancer.Our findings are relevant to document the traditional uses of numerous natural products and to provide background basis to search for novel compounds for cancer therapy. However, the medicinal species with a high FRC could be promising candidates for identifying new bioactive molecules.