D-limonene is a natural bioactive compound found in plant essential oils, known for its broad-spectrum antimicrobial, anthelmintic, insecticidal, and pharmacological properties. It is primarily composed of D-limonene, which is widely present in citrus peels and has a high content (up to 80%). D-limonene exhibits excellent antioxidant, anti-inflammatory, neuroprotective, and antimicrobial effects, making it a promising sustainable alternative to synthetic pesticides and antibiotics. However, its hydrophobic nature and sensitivity to environmental factors limit its application in food and other industries. To enhance its stability and bioactivity, researchers are exploring nanotechnology, such as nanoencapsulation, nanoemulsions, and nanofilms, which improve its physicochemical properties and practical applications. D-limonene has shown significant antimicrobial activity against various bacteria and fungi, including drug-resistant strains, and can inhibit biofilm formation. It also exhibits anthelmintic and insecticidal effects, with potential applications in pest control. In pharmacology, D-limonene demonstrates antioxidant, anti-inflammatory, neuroprotective, and antiviral activities, and may have therapeutic potential for diseases such as Alzheimer's and cancer. Despite its benefits, D-limonene can cause skin sensitization at high concentrations, necessitating further safety evaluations. Its application in food and agriculture is being enhanced through nanotechnology to improve stability, controlled release, and effectiveness. Overall, D-limonene is a promising natural compound with diverse applications, but further research is needed to fully understand its mechanisms and optimize its use.D-limonene is a natural bioactive compound found in plant essential oils, known for its broad-spectrum antimicrobial, anthelmintic, insecticidal, and pharmacological properties. It is primarily composed of D-limonene, which is widely present in citrus peels and has a high content (up to 80%). D-limonene exhibits excellent antioxidant, anti-inflammatory, neuroprotective, and antimicrobial effects, making it a promising sustainable alternative to synthetic pesticides and antibiotics. However, its hydrophobic nature and sensitivity to environmental factors limit its application in food and other industries. To enhance its stability and bioactivity, researchers are exploring nanotechnology, such as nanoencapsulation, nanoemulsions, and nanofilms, which improve its physicochemical properties and practical applications. D-limonene has shown significant antimicrobial activity against various bacteria and fungi, including drug-resistant strains, and can inhibit biofilm formation. It also exhibits anthelmintic and insecticidal effects, with potential applications in pest control. In pharmacology, D-limonene demonstrates antioxidant, anti-inflammatory, neuroprotective, and antiviral activities, and may have therapeutic potential for diseases such as Alzheimer's and cancer. Despite its benefits, D-limonene can cause skin sensitization at high concentrations, necessitating further safety evaluations. Its application in food and agriculture is being enhanced through nanotechnology to improve stability, controlled release, and effectiveness. Overall, D-limonene is a promising natural compound with diverse applications, but further research is needed to fully understand its mechanisms and optimize its use.