The department was established on 5 June 1968 under the name of the Department of Molecular Biology. The department has changed its name several times (Institute for Molecular Biology and Plant Physiology, Department of of Molecular and Structural Biology, Department of Molecular Biology) in connection with mergers with other sections and departments.
On 1 July 2011, the Department of Molecular Biology and Genetics (MBG) was created by merging the Department of Molecular Biology (excluding the research groups within Lipid Biochemistry and Engineering) and the research groups within Molecular Genetics and Biotechnology, Molecular Genetics and System Biology, Quantitative Genetics and Biostatistics from the Department of Genetics and Biotechnology localised at Foulum (by Viborg) and Flakkebjerg (by Slagelse).
In 2019, it was decided that the groups from the Foulum and Flakkebjerg, which the department had merged with in 2011, should no longer be part of the department. The department chose to keep the name Department of Molecular Biology and Genetics, as the department was now known as MBG.
Until 5 January 2022, the department's activities were housed in three different locations, but from that date, all the the groups and students of the department moved together in a common building complex of the former municipal hospital ("Kommunehospitalet").
Read the thesis (in Danish): "Den tidlige molekylærbiologis udvikling og institutionalisering i Danmark",("The development and institutionalization of early molecular biology in Denmark"), where the birth of molecular biology is described.