l-Proline lithium bromide monohydrate (LPLBM) was synthesized and its good quality bulk single crystals of size ~55×10×8 mm3 were grown for the first time. Structural analysis was carried out by using single crystal X-ray diffraction and confirms that the crystal belongs to monoclinic system with space group P21. The lattice parameters of the titled compound was found to be a=8.0347(7) Å, b=5.1469(4) Å, c=10.6218 Å, α=γ=90°, β=104.249(2)° and unit cell volume V=425.74(6) Å3. Elemental analysis was done by electron diffraction X-ray spectroscopy. Optical study shows that the grown crystals are highly transparent (~80%) in entire testing range. Optical band gap was calculated and found to be 5.7 eV. DSC study shows that the grown crystals are thermally stable up to 273 °C and two low temperature phase transitions were observed at −44.66 and 43.95 °C.