in an observer variation study, the agreement rate reached by a pair of observers who measured 85 jejunal biopsy specimens using surface/volume ratio was compared with that reached by a pair of observers who subjectively assessed the same biopsy series. Both the agreement reached between the subjective observers and that reached between the objective observers proved significant by kappa statistics. However, both total and partial kappa values were greater for the pair of objective observers in every diagnostic category. Moreover, the percentage of agreement on the grading of all biopsy specimens, independent of the diagnostic categories, proved significantly higher for the objective observers. In the pair who made a qualitative assessment, interobserver variation was particularly evident in the grading of partial villous atrophy. Contrastingly, in the pair who made a quantitative assessment, agreement was present in all but one slide. The kappa values for the observers examining the same biopsy specimens on two separate occasions indicated closer agreement rates for the two objective observers. It is concluded that morphometric measurement is more reliable than subjective criteria in the assessment of jejunal biopsy specimens and that qualitative assessment of biopsy specimens should be coupled with quantitative histology.