Abstract: Alkali, Alkaline earth and transition metal ions doped L-proline single crystals were grown by solution growth technique. Due to variation in the nature of dopant, there is a modification in the growth habit, nonlinear optical property and mechanical hardness of the doped crystals. Fourier transform infrared (FTIR) spectra reveal strong absorption bands occur due to the presence of L-proline. UV–visible spectra show an improvement in the optical transmittance while doping on L-proline. The unit cell parameters and cell volume are obtained by powder X-ray diffractometer. Effect of dopant on the crystal defect on the grown crystals was characterized by Optical Microscopy. Anti microbial study of the grown crystals were analyzed using gram positive and gram negative micro organisms.