A synergistic disinfectant composition comprises a C1-8 organic acid, an amino acid based surfactant, an anionic surfactant, and a stabilizing agent. The C1-8 organic acid may include two or more types of the C1-8 organic acids with at least one of the C1-8 organic acids is alpha hydroxyl acid. The disinfectant composition has an antimicrobial activity of log reduction of at least 2 under Biocidal Product Registration (BPR) standard EN13727, EN1276, EN13624 or EN1499, and/or the EPA standard that applies the “Quantitative Methods for Evaluating the Activity of Microbicides used on Hard, Non-Porous Surface” issued by the Organisation for Economic Co-operation and Development (OECD). In addition, the disinfectant composition may be stable during storage and retain their antimicrobial activity after at least one month at 40° C. When desired, the synergistic disinfectant composition may further comprise an oxidizing agent.