Based on the review of the literature results the database of the fusion temperatures of two‐component molecular crystals (1947 co‐crystals) and individual components thereof was built up. To improve the design of co‐crystals with predictable melting temperatures, the correlation equations connecting co‐crystals and individual components melting points were deduced. These correlations were discovered for 18 co‐crystals of different stoichiometric compositions. The correlation coefficients were analysed, and the conclusions about the main/determinative and slave components of a co‐crystal were made. The comparative analysis of the melting points of co‐crystals composed from the same components but with different stoichiometry showed a co‐crystal melting temperature growth when increasing the content of a high‐melting component. The differences in the melting temperatures were determined and discussed for the following: (a) monotropic polymorphic forms, (b) two‐component crystals with the same composition and different stoichiometry, and (c) two‐component crystals based on racemates and enantiomers. The database analysis revealed the active pharmaceutical ingredients (APIs) and co‐formers (CFs) more particularly used for co‐crystal design. The approach based on an efficacy parameter allowing the prediction of co‐crystals with melting points lower than those of individual compounds was developed.