Several studies have investigated the physicochemical parameters of PLMs (Pediatric Liquid Medications) to determine their cariogenic and erosive potential. Hence the current study aimed to investigate and compare the cariogenic and erosive effect of the pediatric liquid medications most commonly prescribed in the Bihar region childrens. The present study was planned in Rama Dental, 9 Nehru Nagar, Patliputra, Patna from July 2018 to Dec 2018. Total 40 extracted and carious deciduous molars were used in the present study. The teeth were cleaned using pumice-water slurry and 0.3-µm alumina paste with a polishing brush at low-speed handpiece (5000 rpm) to remove any debris or calculus deposited on to the teeth. Then, they were preserved in artificial saliva and transported to micro hardness testing laboratory. The PLMs included each of the most commonly prescribed nutritional supplements, analgesics, antiasthma tic drugs and artificial saliva as a control It is important to sensitize the parents of the diseased children, paediatricians, pharmacists and the manufacturers to the fact that medicated syrups cause erosion of dental hard tissues. Since the majority of the medicated syrups have acidic pH, the medical and dental specialists should be extra cautious while prescribing syrups and instruct the parents to dilute the prescribed dose of the formulation with water or to rinse their mouth with water soon after ingestion of syrup, if not diluted.