This review summarizes recent advances in nitrogen-containing heterocycles and their biological applications from 2019 to early 2020. Nitrogen-based heterocycles are crucial in medicinal chemistry, with over 75% of FDA-approved drugs containing nitrogen heterocycles. These compounds are vital for drug design due to their ability to form hydrogen bonds with biological targets, leading to various therapeutic applications. The review highlights the importance of nitrogen-based heterocycles in drug development, particularly in treating diseases such as cancer, diabetes, and tuberculosis. The review discusses various nitrogen-containing heterocycles, including β-lactams, 1,2,3-triazoles, imidazoles, pyrazoles, and thiazoles. β-lactams are important in antibiotics and have shown significant activity against bacterial strains. 1,2,3-triazoles are valuable pharmacophores with broad biological activities, including anti-tubercular, antiviral, and anti-diabetic effects. Imidazoles and benzoimidazoles have shown potential in cancer treatment and as anti-diabetic agents. Pyrazoles have been studied for their anti-inflammatory, anti-cancer, and anti-mycobacterial activities. The review also discusses the structural features and biological activities of these heterocycles, emphasizing the role of substituents and their impact on activity. The importance of nitrogen-based heterocycles in drug development is highlighted, with many compounds showing promising results in preclinical studies. The review concludes that nitrogen-containing heterocycles are promising candidates for the development of new drugs, particularly in the treatment of various diseases.This review summarizes recent advances in nitrogen-containing heterocycles and their biological applications from 2019 to early 2020. Nitrogen-based heterocycles are crucial in medicinal chemistry, with over 75% of FDA-approved drugs containing nitrogen heterocycles. These compounds are vital for drug design due to their ability to form hydrogen bonds with biological targets, leading to various therapeutic applications. The review highlights the importance of nitrogen-based heterocycles in drug development, particularly in treating diseases such as cancer, diabetes, and tuberculosis. The review discusses various nitrogen-containing heterocycles, including β-lactams, 1,2,3-triazoles, imidazoles, pyrazoles, and thiazoles. β-lactams are important in antibiotics and have shown significant activity against bacterial strains. 1,2,3-triazoles are valuable pharmacophores with broad biological activities, including anti-tubercular, antiviral, and anti-diabetic effects. Imidazoles and benzoimidazoles have shown potential in cancer treatment and as anti-diabetic agents. Pyrazoles have been studied for their anti-inflammatory, anti-cancer, and anti-mycobacterial activities. The review also discusses the structural features and biological activities of these heterocycles, emphasizing the role of substituents and their impact on activity. The importance of nitrogen-based heterocycles in drug development is highlighted, with many compounds showing promising results in preclinical studies. The review concludes that nitrogen-containing heterocycles are promising candidates for the development of new drugs, particularly in the treatment of various diseases.