This review discusses the development of lead-free piezoelectric materials as alternatives to lead-based materials like PZT, which are toxic and environmentally harmful. Lead zirconate titanate (PZT) is well-known for its excellent piezoelectric properties but is being replaced due to its toxicity and environmental concerns. The European Union has implemented regulations to restrict the use of lead and other heavy metals, prompting research into lead-free materials. Several lead-free piezoelectric materials, such as bismuth sodium titanate (BNT), alkali niobates (e.g., KNbO3), and non-perovskite materials like bismuth layer-structured ferroelectrics, have been investigated. These materials show promising piezoelectric properties, though they do not yet match the performance of PZT. The study highlights the importance of structure-property relationships, doping, and processing techniques in enhancing the performance of lead-free materials. Perovskite-type materials, such as BNT and KNbO3, are particularly promising due to their high Curie temperatures and good piezoelectric properties. Doping with elements like lanthanum, cerium, and niobium has been shown to improve the piezoelectric response of these materials. Non-perovskite materials, such as bismuth layer-structured ferroelectrics, are also being explored for their high Curie temperatures and anisotropic piezoelectric properties. The review also discusses the challenges in processing lead-free piezoelectric materials, including difficulties in achieving high density and uniformity. Various processing methods, such as sol-gel, wet-chemical, and co-precipitation, have been used to synthesize these materials. The study emphasizes the need for further research to develop lead-free materials that can match the performance of PZT while being environmentally friendly. In conclusion, lead-free piezoelectric materials are gaining attention as alternatives to PZT due to their environmental benefits. While they show promise, further research is needed to improve their performance and make them suitable for a wide range of applications.This review discusses the development of lead-free piezoelectric materials as alternatives to lead-based materials like PZT, which are toxic and environmentally harmful. Lead zirconate titanate (PZT) is well-known for its excellent piezoelectric properties but is being replaced due to its toxicity and environmental concerns. The European Union has implemented regulations to restrict the use of lead and other heavy metals, prompting research into lead-free materials. Several lead-free piezoelectric materials, such as bismuth sodium titanate (BNT), alkali niobates (e.g., KNbO3), and non-perovskite materials like bismuth layer-structured ferroelectrics, have been investigated. These materials show promising piezoelectric properties, though they do not yet match the performance of PZT. The study highlights the importance of structure-property relationships, doping, and processing techniques in enhancing the performance of lead-free materials. Perovskite-type materials, such as BNT and KNbO3, are particularly promising due to their high Curie temperatures and good piezoelectric properties. Doping with elements like lanthanum, cerium, and niobium has been shown to improve the piezoelectric response of these materials. Non-perovskite materials, such as bismuth layer-structured ferroelectrics, are also being explored for their high Curie temperatures and anisotropic piezoelectric properties. The review also discusses the challenges in processing lead-free piezoelectric materials, including difficulties in achieving high density and uniformity. Various processing methods, such as sol-gel, wet-chemical, and co-precipitation, have been used to synthesize these materials. The study emphasizes the need for further research to develop lead-free materials that can match the performance of PZT while being environmentally friendly. In conclusion, lead-free piezoelectric materials are gaining attention as alternatives to PZT due to their environmental benefits. While they show promise, further research is needed to improve their performance and make them suitable for a wide range of applications.