Bone morphogenetic proteins (BMPs) are members of the transforming growth factor-β (TGF-β) family and play crucial roles in various biological processes, including bone and cartilage formation, tooth development, kidney function, and vascular homeostasis. BMPs bind to type II and type I serine-threonine kinase receptors, which transduce signals through Smad and non-Smad pathways. Recent studies have revealed that BMP signaling is finely regulated by various mechanisms, both positively and negatively. Disruptions in BMP signaling pathways are linked to a wide range of clinical disorders, such as vascular diseases, skeletal diseases, and cancer. Therapeutic approaches, including the administration of recombinant BMP ligands and increasing endogenous BMP expression, have shown promise in treating certain diseases. Additionally, the development of BMP receptor inhibitors may prove useful for treating clinical diseases induced by hyperactivation of BMP signaling pathways. The review discusses the recent advances in understanding BMP receptors and signaling pathways in mammals. It covers the structure and function of BMP receptors, including type I and type II receptors, and their coreceptors. The review also delves into the mechanisms of ligand binding, receptor activation, and signal transduction through Smad proteins. The roles of Smads in intracellular signaling, including their interaction with transcription factors and coactivators, are highlighted. The review further explores the regulation of Smad signaling by I-Smads, ubiquitin-proteasome pathways, and other mechanisms. Finally, it discusses the impact of mutations in BMP-specific R-Smads, co-Smads, and I-Smads on various biological processes and diseases.Bone morphogenetic proteins (BMPs) are members of the transforming growth factor-β (TGF-β) family and play crucial roles in various biological processes, including bone and cartilage formation, tooth development, kidney function, and vascular homeostasis. BMPs bind to type II and type I serine-threonine kinase receptors, which transduce signals through Smad and non-Smad pathways. Recent studies have revealed that BMP signaling is finely regulated by various mechanisms, both positively and negatively. Disruptions in BMP signaling pathways are linked to a wide range of clinical disorders, such as vascular diseases, skeletal diseases, and cancer. Therapeutic approaches, including the administration of recombinant BMP ligands and increasing endogenous BMP expression, have shown promise in treating certain diseases. Additionally, the development of BMP receptor inhibitors may prove useful for treating clinical diseases induced by hyperactivation of BMP signaling pathways. The review discusses the recent advances in understanding BMP receptors and signaling pathways in mammals. It covers the structure and function of BMP receptors, including type I and type II receptors, and their coreceptors. The review also delves into the mechanisms of ligand binding, receptor activation, and signal transduction through Smad proteins. The roles of Smads in intracellular signaling, including their interaction with transcription factors and coactivators, are highlighted. The review further explores the regulation of Smad signaling by I-Smads, ubiquitin-proteasome pathways, and other mechanisms. Finally, it discusses the impact of mutations in BMP-specific R-Smads, co-Smads, and I-Smads on various biological processes and diseases.