The ratio of total surface area to projected leaf area was determined for mature foliage samples collected at three canopy heights from Juniperus virginiana and J. scopulorum from four seed sources grown in southeastern Nebraska. The relation of projected leaf area to leaf dry weight and volume was also determined. Total surface area was estimated to be 3.2 times the projected surface area. This relationship was independent of seed source or crown position. Projected leaf area can be satisfactorily estimated from weight or volume. However, these relationships differed by crown position or seed source. These results indicate that leaf area of mature juniper foliage may be rapidly estimated through measurement of projected surface area. Further, the leaf area of large samples may be estimated by determining the appropriate specific leaf area or surface-to-volume ratios. For. Sci. 38(1):61-67.