Seven commercial ultra narrow row (UNR) cotton fields were monitored on a weekly basis in Maricopa County, AZ in 1999. Varieties of Delta Pine and Sure Grow were planted from April 15 to June 1 and reached cut-out after accumulating 1913 to 2327 heat units after planting. Average yield for UNR cotton was 2.1 bales per acre which was 0.4 bales per acre lower than the five year average for cotton planted on conventional row spacings. Fiber quality from gin records for 801 bales had average micronaire readings of 4.54 and grades of 11 and 21 for 74% of bales. Discounts for extraneous matter (bark, grass, and cracked seed) was 5.4% and average strength (34.8) and staple lengths (27.12) were in acceptable ranges. Total cash costs ranged from $450 to $705.