Scalable synthesis of 2D materials is a prerequisite for their commercial exploitation. Here, a novel method of producing nanocrystalline molybdenum disulfide (MoS2) at the liquid-liquid interface is demonstrated by decomposing a molecular precursor (tetrakis(N,N-diethyldithiocarbamato) molybdenum(IV)) in an organic solvent. The decomposition occurs over a few hours at room temperature without stirring or the addition of any surfactants, producing MoS2, which can be isolated onto substrates of choice. The formation of MoS2 at the liquid-liquid interface can be accelerated by the inclusion of hydroxide ions in the aqueous phase, which we propose to act as a catalyst. The precursor concentration was varied to min-imize MoS2 thickness and the organic solvent was chosen to optimize the speed and quality of formation. The kinetics of the MoS2 formation have been investigated and a reaction mechanism has been proposed. The synthesis method is, to the best of our knowledge, the first reported room temperature synthesis of transition metal dichalcogenides, offering a potential solution to scalable 2D material production.