To find correlations for heat transfer to water walls and wing walls in commercial circulating fluidized-bed (CFB) boilers, data on overall heat absorption rates, bed temperature and suspension density from two commercially operating CFB boilers (100 and 700 t h(-1) capacities) were analyzed. A methodology was developed to deduce heat transfer coefficients on wing walls from the measured overall heat duties of the entire evaporator. Heat transfer coefficients on water walls are found to be higher than those on wing walls. A correlation was developed relating the heat transfer coefficients, averaged over the entire height of the heat absorbing wall, with operating parameters. This makes the correlation simple to use in boiler designs and it reduces uncertainties in measured data. The correlation is tested against heat transfer coefficients measured and reported by other researchers. This deviation is within 15% which is of the same order as the uncertainty in measured data.