Corneal asphericity (the p-value, p) and apical corneal radius (r0) were calculated for 63 Hong Kong-Chinese (39 male and 24 female), using the Topographic Modeling System (TMS-1). The values of p and r0 in, and between, the two principal meridians were compared, and the effects of refractive error and gender were also investigated. The mean +/- SD r0 and p along the flattest meridian of the right eye were 7.82 +/- 0.26 mm and 0.78 +/- 0.12 respectively. The mean +/- SD r0 and p along the steepest meridian of the right eye were 7.64 +/- 0.26 mm and 0.83 +/- 0.15 respectively. Meridional variations were found in r0 and in p. There was no correlation between p and r0 along the two principal meridians. p was not significantly correlated to the refractive error but r0 was. Our results agree with previous findings that while males have longer r0 than females, their p are not significantly different.