Bell pepper is a relatively new vegetable plant known in Indonesia. Bell pepper has a great potential to be developed in Indonesia, this is shown by the high public interest in consuming. However, this high demand has not been fully met by farmers. It’s because bell pepper production is determined by several factors, one of which is the attack of plant disturbing organisms (OPT). The most detrimental plant disturbing organisms for bell pepper cultivation is Thrips parvispinus Karny these insect damage caused are widely known as pests on various agricultural commodities and are polyphagous. Damage caused by Thrips parvispinus Karny in pepper plants ranges from 12% -74%. Therefore, it’s necessary to carry out environmentally friendly control efforts, one of which is by utilizing a mixture of neem leaves (Azadirachta indicca A. Juss.) and B.bassiana fungus as a vegetable pesticide. This study aims to determine the compatibility of a mixture of neem leaves and B.bassiana in increasing the mortality of Thrips parvispinus Karny on bell pepper plants. The research was conducted from August to November 2022. The research method used a randomized block design consisting of nine treatments and three repetitions with details of the treatments, namely: F0: control (no treatment), F1: 40 ml/l neem leaves plus 20 grams/l B.bassiana, F2: 50 ml/l neem leaf pesticide plus 30 gram/l B.bassiana, F3: 60 ml/l neem leaf plus 40 gram/l B.bassiana, F4: 70 ml/l neem leaf plus 50 gram /l B.bassiana, F5: 80 ml/l neem leaves plus 60 grams/l B.bassiana. The conclusion obtained is that the application mixture of 80 ml/l neem leaves plus 60 grams/l B.bassiana can increase and accelerate the mortality time of Thrips parvispinus Karny pest.