Three new solvates of 4,6-diamino-2-cyclopropylamino-5-pyrimidine carbonitrile (DCL): crystal 1 (DCL with N,N-dimethylformamide (DMF)), crystal 2 (DCL with methanol) and crystal 3 (DCL with water) were synthesized and characterized by single-crystal X-ray diffraction, thermal behaviour, Hirshfeld surface and powder X-ray powder diffraction (PXRD). ¹H and ¹³C NMR spectra confirm solvent molecules existing in the crystal lattice. Crystal 1 forms a 1:1 DCL:DMF crystal; crystal 2 gives a 1:0.5 DCL:methanol crystal and crystal 3 gets a 1:1.5 DCL:H₂O crystal. The three crystals are all primarily stabilized by a strong N–H×××N hydrogen bonding interaction between DCL and the solvents. The structures are stabilized by H×××H, N–H×××O, N–H×××N and O–H×××O intermolecular interactions. When crystal 2 is dried at 150 °C, the new polymorph with no solvate is obtained.