Referring to Baddeley's (1986) working memory model, to the processing efficiency theory (Eysenck, 1983, 1992), and to the finding that decreasing rehearsal rate is an important factor for age deficits in the processing efficiency of working memory (cf. Hasselhorn, 1990) it is claimed that state-anxiety as well as age reduce rehearsal rate (but not structural storage capacity) and thus impair the functional capacity of working memory. 130 young and 40 old Ss participated in a study where state-anxiety, speech rate (as a rehearsal rate measure), and memory spans for phonological similar and dissimilar words (to quantify the efficiency of the structural storage) were collected. The predicted effects of state-anxiety on speech rate was found for both age groups. However, the independence of anxiety and the structural storage component was only confirmed for young Ss. Although old Ss showed a lower level of anxiety than young Ss, the detrimental effects of anxiety on working memory seems to be more pronounced in old age.