Arsenic contamination in drinking water is one of the major causes of arsenicosis, a clinical syndrome due to drinking arsenic-rich water. Data on arsenic concentration levels in drinking water is lacking in Pakistan. Knowledge of arsenic concentration in ground water used for drinking is essential to introduce a strategy to avoid arsenic contamination associated with health hazards. The present work deals with the assessment of arsenic concentration levels in ground water in eight provincial districts of Punjab, Pakistan. During a study conducted in 2001-03 by the provincial Local Government and Community Development department in the Punjab province, 4,547 drinking water samples were collected and analyzed using atomic absorption spectrometry technique. The results show that arsenic levels in drinking water varied from 6 to 12 ng ml^-1 with a mean value of 8.5±1.6 ng ml^-1, which is below the recommended World Health Organization (WHO) guidelines of 10 ng ml^-1 for drinking water. The data generated in this study will provide base line values for monitoring arsenic concentrations in drinking water in the surveyed area.