The use of plant protection products ensures effective protection of agricultural crops with quality and high yields. The negative effects of plant protection products are primarily reflected in the occurrence of resistance, pesticide residues in the environment and loss of biodiversity. The need to introduce alternative pest control methods that are both effective and safe for producers, consumers and the environment is increasingly emphasized. A possible alternative in plant protection is the use of ozone (O3). Ozone is a gas that is naturally found in the Earth's stratosphere, and is very simply artificially produced by electrical discharge. Its disinfectant properties and applications in the healthcare and food industries have long been known. In the last 20 years, the possibility of its application in agriculture, primarily in protection against harmful organisms, has been investigated. The paper presents an overview of current knowledge on the effectiveness of ozone on harmful insects and details of experiments conducted in Croatia and abroad. In addition to high efficiency indoors (warehouses, silos) on all types of harmful organisms (insects, mites, diseases), ozone treatments are imposed as a potential solution for effective pest control in open spaces (orchards, vineyards, etc.). Ozone in amounts greater than 2 ppm effectively suppresses bacteria, viruses, fungi and numerous insects It does not show environmental toxicity, it decomposes under normal conditions into oxygen within only 30 minutes, leaves no residues and no adverse effects on human health. The application of ozone is an alternative to traditional insecticides and fungicides as a biofumigant against a number of pests, microorganisms and mycotoxins and is certainly a method that has a future in plant protection.