The article provides an overview of Online Mendelian Inheritance in Man (OMIM), a comprehensive public database of bibliographic information about human genes and genetic disorders. Initially conceived by Dr. Victor McKusick as *Mendelian Inheritance in Man* (MIM), OMIM is now distributed electronically by the National Center for Biotechnology Information (NCBI). Each entry in OMIM includes a full text summary of a genetic phenotype or gene, along with extensive links to other genetic resources such as DNA and protein sequences, PubMed references, mutation databases, and approved gene nomenclature. OMIM is widely used by clinicians, students, and researchers for differential diagnosis, teaching, and research. The database is curated by geneticists and molecular biologists, ensuring its authority and timeliness. Key features of OMIM include standardized entry formats, clinical synopses, allelic variant lists, and integration with other databases. The article also discusses the future of OMIM, emphasizing its continued growth and the importance of maintaining its standards as new genetic discoveries are made.The article provides an overview of Online Mendelian Inheritance in Man (OMIM), a comprehensive public database of bibliographic information about human genes and genetic disorders. Initially conceived by Dr. Victor McKusick as *Mendelian Inheritance in Man* (MIM), OMIM is now distributed electronically by the National Center for Biotechnology Information (NCBI). Each entry in OMIM includes a full text summary of a genetic phenotype or gene, along with extensive links to other genetic resources such as DNA and protein sequences, PubMed references, mutation databases, and approved gene nomenclature. OMIM is widely used by clinicians, students, and researchers for differential diagnosis, teaching, and research. The database is curated by geneticists and molecular biologists, ensuring its authority and timeliness. Key features of OMIM include standardized entry formats, clinical synopses, allelic variant lists, and integration with other databases. The article also discusses the future of OMIM, emphasizing its continued growth and the importance of maintaining its standards as new genetic discoveries are made.