It was hypothesized that the daily intake of a geriatric preparation containing vitamins, minerals, trace elements and ginseng, would strengthen the sleep‐wake rhythm and thus have a positive influence upon characteristics of sleep. A total of 32 subjects (age 61 ‐92, mean 78 yr, 23 females) was recruited from a local elderly home. In a double‐blind procedure 16 subjects received the geriatric preparation for a period of 10 weeks, while the other 16 subjects received a placebo. Before treatment, a 48‐hour polygraphic home‐recording was made of the EEG, and ‐ during sleep ‐ of the chin EMG, the EOG and respiration. At the end of the treatment period ( 10 weeks later) this recording was repeated. After exclusion of low‐quality recordings, the data of two groups of 10 subjects each were analyzed. The results show a significantly increased percentage of REM sleep for the experimental group after treatment, and a similar trend for Slow Wave Sleep. Moreover, inspection of the spectra of the 24‐hour EEG recordings suggests an increased circadian amplitude of the low‐frequency EEG.