This study examined caries level, amount of calculus, and oral microbial environment in gastrostomy tube (GT)-fed children compared with healthy children and children with disabilities orally fed (PO). Study design.: The study group consisted of 12 GT-fed children and the two control groups consisted of 16 children with disabilities orally fed and 17 healthy children. DMF-T/dmf-t index, calculus index, Mutans Streptococci (MS), Lactobacilli (LB) levels and salivary buffer capacity were examined. Results.: DMF-T/dmf-t index was significantly lower in the tube-fed group. Calculus index was highest in the tube-fed group. MS and LB levels were the lowest in the tube-fed children. Correlation was found between MS and DMF-T/dmf-t. Conclusions.: Tube-fed children demonstrated significantly higher calculus levels and less caries, MS, and LB levels then healthy children or children with disabilities eating PO.