Technical Abstract: Doubling the plant density in transplanted non-pungent jalapeno peppers (Capsicum annuum Mill.) improves yield. However, it is not known how other spacings affect yield. In-row plant spacing was examined to determine how it affects development of these peppers. Transplants of a non-pungent jalapeno, cv. Pace105, were established at spacings of 8, 16, 24, 32, 40 and 48 cm between plants in mid-April of 2006 and 2007 and in early-July in 2007. Fruit were harvested once when 5% of marketable size pods in rows were red. Distance to first flower, and yield characters were determined. Fruit were culled based on size and presence of blemishes. Height on the stem to the first flower averaged 15.8 cm over all treatments. Plants in the Spring 2006 season had the highest marketable and cull yields. Numbers of marketable fruit¿ha**-1 were higher at the 8 cm spacing than at the 40 or 48 cm in-row spacings. There was little difference in marketable yield due to in-row spacing. The greatest number of cull fruit per plant were on plants spaced 48 cm apart. Plant spacing had no affect on number of cull fruit or cull yield¿ha**-1. Overall culls accounted for about 22% of total yield. Individual cull fruit weights were about 50% less than for marketable fruit. Spacings tested did not appear to greatly affect development and yield of this pepper. This will allow producers to have the option of either using fewer plants on the same amount of land, or more plants on less land without much reduction of quantity or quality of yield.