The article presents the results of pesticidal activity study of product elaborated on the neem oil base. Neem extract (Azadirachta indica L.) is a product that can be used as an alternative to combat pests such as some species of insects and mites. In the present study, we aimed to evaluate the biological efficacy of neem extract in combating aphids and mites in cucumber culture. The experiments were carried out in the experimental greenhouse of the IGFPP. Four experimental variants of three repetitions each were used in the research. Thus, the experiment scheme included two different concentrations of neem oil, the standard (Pelecol) and the untreated control. The experimental parcels were located according to the randomized block method. During the vegetation period, 2 treatments were carried out. The term of treatment was determined according to the biological characteristics, the numerical density and the spread degree of the pests. After two treatments with an interval of ten days between them it was determined that the higher concentration of neem oil showed higher biological efficacy compared to the lower one. This fact is due to the active substance of the extract (Azadirachtin), which reduces the feeding of insects and acts as a repellent against aphids, which stop feeding and populating the treated plant. However, after carrying out the 2nd treatment on the cucumber plants, mites appeared, the biological effectiveness of the extract in combating them being lower. In conclusion, it can be mentioned that neem extract (Azadirachta indica L.) represents a viable alternative for the control of pests (especially aphids) of cucumber plants in protected space.