The greenhouse whitefly, Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae), is a major insect pest of tomato under field and greenhouse conditions, and its management is based primarily on foliar applications of insecticides. However, the continuous use of conventional insecticides leads to the development of insecticide resistance, which emphasizes the need for new pest management alternatives. The present study was conducted to investigate the efficacy of insecticides and bio-pesticides against the greenhouse whitefly on tomatoes grown in polyhouses (plastic-covered greenhouses) for two years at Palampur, Himachal Pradesh, India. Results showed that abamectin resulted in the highest mean percent reduction in immatures of T. vaporariorum, followed by acetamiprid and buprofezin. Spiromesifen and bifenthrin resulted in moderate levels of efficacy, followed by azadirachtin and mineral oil. Spinosad, Melia, and malathion (the insecticide-treated control) showed the least efficacy against immatures of T. vaporariorum. Similarly, abamectin and acetamiprid were the most highly effective materials against the adult stage. Bifenthrin, spinosad, azadirachtin, and buprofezin showed moderate reductions in adult whitefly populations. Spiromesifen, mineral oil, Melia, and malathion were the least effective against adult populations of T. vaporariorum. Overall, abamectin, acetamiprid, buprofezin, and bifenthrin were the most promising materials for managing T. vaporariorum in greenhouses. Azadirachtin and mineral oil also provided adequate control of greenhouse whitefly on greenhouse tomatoes.