In this study the validity of partial dictation as a measure of overall language proficiency was examined. Two partial dictation tests along with a C-Test, a cloze test, and a reading comprehension test, as criterion measures, were administered to a group of Iranian EFL learners. The coefficients of correlation between partial dictation and criterion measures were computed. Correlations revealed that partial dictation highly correlates with the cloze test, the C-Test, and the reading comprehension test. Principal components analysis showed that all the variables (four C-Test passages, two dictation passages, one cloze passage, and one reading comprehension passage) formed one single factor which explained 58% of the variance. All the variables had high loadings on the factor. These findings were interpreted as evidence of the similarity of the construct measured by partial dictation and other measures employed in the study. Desiderata for future research and potential applications of partial dictation in foreign language testing and teaching are discussed.