Traditional agriculture suffers from problems such as the use of chemical pesticides, which harm the environment and human health. This has led to the emergence of the concept of biological control, which involves using microorganisms to combat agricultural pests in natural and safe ways. What is biological control? Biological control means using living organisms, such as bacteria, fungi, or viruses, to fight plant pests or diseases instead of using synthetic pesticides. Examples of microorganisms used in agriculture: 1. Bacillus thuringiensis (Bt): Produces toxins that kill the larvae of harmful insects and is widely used in crop spraying. 2. Trichoderma fungi: Attack harmful fungi in the soil and prevent them from infecting roots. 3. Nitrogen-fixing bacteria such as Rhizobium: Help plants grow by naturally supplying them with nitrogen. Benefits of biological control: • Reduced reliance on chemicals. • Maintaining ecological balance. • Promoting soil and crop health. • Reducing farming costs in the long run. Conclusion The use of microorganisms in biological control represents a step towards sustainable and environmentally friendly agriculture. As research continues, these methods are expected to become more efficient and widely adopted in the future. Al-Mustaqbal University, the leading university in Iraq.