Molybdenum disulfide (MoS ) nanosheets have attracted great scientific interest for their remarkable electronic and optical properties. During the last few years significant progress on exfoliation methods of such nanosheets allowed the development of surface functionalization in covalent or noncovalent fashion. Markedly, the chemical modification allows tailoring and tuning the optical and electronic characteristics of MoS , opening new avenues for the potentiality of MoS -based hybrids in diverse technological fields. Physisorption of organic molecules onto MoS through the development of numerous van der Waals interactions is the most widely approach employed for the surface noncovalent immobilization of organic species onto MoS nanosheets. Conversely, developed strategies for the edge and in-plane covalent functionalization of MoS mainly concern chemistry at S vacancies, direct C-S bond formation, and coordination of S edges at metal centers. Herein, we focus into the most representative molecular doping strategies and material designing of MoS -based hybrid nanostructures carrying photo- and/or electro-active components. Key points related with the exfoliation routes, the surface functionalization approaches and their impact on the electronic properties of the functionalized nanosheets are comprehensively discussed, offering a toolbox for scientists of different disciplines interested in putting a step forward in the field of transition-metal dichalcogenide-based materials.