Different concentrations of three artificial sweeteners (aspartame, sorbitol and sucralose) as well as two different exposure times (24 and 48 hrs) were applied to investigate the cytogenetical, biochemical andmolecu-lar alterations in onion (Allium cepaL.) meristematic cells. The results indicated that all the treatments induced different types of chromosomal abnormalities in non dividing cells (interphase) as well as different mitotic stages. The abnormalityobserved in interphase was micronucleus. At prophase stage small or large micronucleus appeared. Metaphase aberrations represent the most conspicuous type of abnormalities. A number of abnormalities at ana-phase and telophase were noticed such as bridges, diagonal, disturbed and late separation.Biochemical study in-cludes protein profile using polyacrylamide gel electrophoresis (SDS-PAGE) technique. The electrophoretic analysis of extracted proteins showed 18 bands with the molecular weight ranging from 41.70 to 96.36 KDa. There are 8 monomorphic bands and 10 polymorphic bands. Molecular study using inter simple sequence repeats DNA (ISSR-DNA) technique. Four primers were used and the total number of bands 34 from which 12 were common in control and all treatments of the artificial sweeteners and 22 were polymorphic bands.