The study examined a modification of two sets of previously published LNNB‐derived WAIS IQ estimates in order to estimate WAIS‐R IQs in a sample of neuropsychiatric patients. Findings suggested that the modification will allow practicing clinicians to estimate WAIS‐R IQs with a level of accuracy similar to that found in previous research. The level of predictive accuracy for WAIS‐R FSIQ and VIQ was somewhat higher than would be expected on the basis of previous research, which suggests that the modified McKay, Golden, Moses, Fishburne, and Wisniewski (1981) formulae for estimating IQ may be more accurate than previously thought. The correlation matrix of WAIS‐R subtests and LNNB Form I clinical and summary scales also is described.