Ammonium acetate doped ammonium dihydrogen phosphate single crystals have been grown by slow cooling along with bidirectional seed rotation method. Effects of ammonium acetate on the solubility, growth rate, structural, optical, mechanical, dielectric properties, crystalline perfection and second harmonic generation efficiency of the crystals have been investigated. The high-resolution X-ray diffraction study shows that the crystalline perfection of the doped crystal is good. Fourier transform infrared studies confirm the functional groups of the crystals. It is seen from UV-vis studies that the optical transparency is increased much by the dopant. Vickers hardness measurements reveal the mechanical stability of the crystals. Low dielectric losses were observed from the dielectric measurements for the doped ADP crystals at higher frequencies. The relative SHG efficiency measurements revealed that the dopant has enhanced the efficiency. (C) 2010 Elsevier B.V. All rights reserved.