The Linguistic Inquiry and Word Count (LIWC) text analysis program often is used as a measure of emotion expression, yet the construct validity of its use for this purpose has not been examined. Three experimental studies assessed whether the LIWC counts of emotion processes words are sensitive to verbal expression of sadness and amusement. Experiment 1 determined that sad and amusing written autobiographical memories differed in LIWC emotion counts in expected ways. Experiment 2 revealed that reactions to emotionally provocative film clips designed to manipulate the momentary experience of sadness and amusement differed in LIWC counts. Experiment 3 replicated the findings of Experiment 2 and found generally weak relations between LIWC emotion counts and individual differences in emotional reactivity, dispositional expressivity, and personality. The LIWC therefore appears to be a valid method for measuring verbal expression of emotion.