Abstract: Hair is evaluated and compared with urine as a biomonitor for human intake of uranium. Concentrations of 234U and 238U and the activity ratio between them are measured in the hair, urine, and drinking water of 24 drilled bedrock well water users in Östergötland, Sweden. The samples are measured with α-spectrometry after radiochemical preparation using liquid-liquid separation with tributylphosphate. The results show that there is a stronger correlation between the uranium concentrations in the drinking water of each subject and the hair of the subject (r2 = 0.50) than with the urine (r2 = 0.21). There is also a stronger correlation between the activity ratios of water and hair (r2 = 0.91) than between water and urine (r2 = 0.56). These results imply that hair may serve as a robust indicator of chronic uranium intake. One obvious advantage over sampling urine is that hair samples reflect a much longer excretion period: weeks compared to days. The absorbed fraction of uranium, the f value, is calculated as the ratio between the excreted amount of uranium in urine and hair per day and the daily drinking water intake of uranium. The f values stretch from 0.002 to 0.10 with a median of 0.023.