Abstract:Opuntia ficus-indica belongs to the Cactaceae family and is widespread in semi-arid and arid regions. Cactus pears are known for their health promoting properties which are due to a variety of bioactive molecules. This study aims to identify and quantify phenolic acids, flavonoids and betanin from spineless Opuntia ficus-indica fruits. Fresh mature samples were crushed, and extracted with 50% aqueous ethanol. The identification process was carried out using a Shimadzu high performance liquid chromagraph equipped with a quadrupole mass spectrum. Quantification was made using calibration curves of analytical standards. 9 phenolic acids, 1 flavan-3-ol, 2 flavanones, 3 flavonols, 6 flavones and 2 betacyanins were identified. Important levels of betanin, quinic acid, cirsiliol, acacetin, transcinnamic acid, rutin and naringin were calculated. Our results indicated that Opuntia ficus-indica fruits are an important dietary source of phenolic compounds and betalains with high antioxidant capacity.