Dose tables are given for 125I implants, as well as detailed information about the dose distribution which is calculated for different square planar and cubic volume implants using recently published depth dose data. Minimum peripheral and maximum central doses are evaluated for different areas and volumes for seeds with 1 mCi (37 MBq) equivalent activy and spaced 1 cm apart. The dose delivered at any specific point in a permanent implant is the dose rate at that point multiplied by the mean life (2,080 hrs) and the activity per seed (1 mCi). The effect of spacing is studied and a spacing rule is suggested.