Agricultural crops face numerous pest-problems, particularly due to aphids, scale-insects, mealybugs, white-flies, mites, etc. Aphids (Homoptera: Aphididae) are one of the important pests of crops, and are highly injurious for cultivated and non-cultivated crops. We reported eighteen aphid species belong to twelve genera in Kumaun region. There are eight species of Aphis, two species each of Macrosiphum and Rhopalosiphum, and one species each Brevicoryne, Ceratovacuna, Hyperomyzus, Lipaphis, Macrosiphoniella, and Metopolophium infesting severalcultivated and non-cultivated crops. We are also reporting fifty-five host plants in Kumaun region of Uttarakhandbelonging to 18 families, viz. Anacardiaceae, Apiaceae, Apocynaceae, Araceae, Asteraceae, Brassicaceae, Commelinaceae, Cucurbitaceae, Fabaceae, Lamiaceae, Malvaceae, Myrtaceae, Poaceae, Punicaceae, Ranunculaceae, Rosaceae, Rutaceae and Solanaceae