Whiteware compositions prepared using Pugu kaolin and industrial grade quartz and feldspar were studied with respect to varying sintering temperatures. The strength developed was correlated to mullite (3Al 2 O 3 .2SiO 2) content and the microstructure. It was observed that within the vitrification temperature range, the strength mainly depended on the mullite content and the bulk density. Above the vitrification temperature range the deterioration of the strength is due to the coarsening of mullite needles and bloating.