Objective: The NART-2 and WTAR are used to estimate premorbid intellectual functioning. There are concerns about their accuracy. Our aim was to develop models predicting WASI-II scores from the NART-2 and WTAR variables and evaluate their accuracy within an Australian sample.

Method: The sample included 145 adults aged 18.91 to 70.64 years (M = 34.70, SD = 13.30), of which 78 were female. Analyses examined the reliability of the word reading tasks and estimated WASI-II sores with multiple linear regression. Comparison of estimated scores were made with actual WASI-II scores.

Results: WASI-II scores were moderately related to word reading tasks (r = .33 to.51, p < .01) and weakly related to age, years of education, and occupation. Models were identified for the four WASI-II index scores (with R2 = .20 to .36) and their accuracy checked. 24%-48%, 61%-73% and 80%-88% were correctly estimated within five, 10 and 15 points, respectively.

Conclusions: Models for predicting WASI-II scores from the NART-2 and WTAR and demographic variables had adequate strength and accuracy. However, they were likely to be limited to those with FSIQ>79. Further development of word reading tasks for the prediction of premorbid intellectual functioning in the contemporary Australian context is warranted.