Sulfanilic acid (SFA) crystal is well known as an effective material for photonic, electro-optical, harmonic generating and biomedical applications. A well-known nonlinear optical material, a high-quality SFA single crystal made utilizing the slow evaporation solution method (SEST) is the subject of this article. A 75 days development period yielded a transparent SFA single crystal measuring 5 × 5 × 2 mm