Aspartame (ASP) is one of the most controversial food additives found in various food products all over the world. Once ingested, ASP is metabolized to phenylalanine, aspartic acid, and methanol. The aims of the study are to evaluate the effects of ASP administration on the dorsal surface of rats' tongues and to investigate the possible protective effect of Platelet-rich plasma (PRP). Thirty adult male albino rats were used and divided into three equal groups. The control group received the vehicle only. ASP group received a dose of 250 mg/kg b wt for four weeks while the PRP group were treated as ASP group, in addition they received a single local injection with PRP in the right lateral border of the tongue. The most obvious changes were loss of normal conical appearance with hyperkeratosis of filiform papillae. The epithelial cells showed hyperplasia (acanthosis), cellular pleomorphism and nuclear hyperchromatism. Distorted and atrophied fungiform papilla with degeneration of epithelial cells and pyknotic nuclei were visible. In the lamina propria numerous dilated and congested blood vessels were obvious. SEM examination revealed disfigurement of tongue papillae. The fungiform papillae showed irregular wrinkled surface and ill-defined taste pore. PRP treatment almost restored the normal architecture of tongue papillae. Chronic aspartame ingestion could result in marked morphological alteration of dorsal surface of the tongue and PRP exerted a protective role against this effect.