Textile manufacturers have raised concerns that mill performance of cotton (Gossypium hirsutum L.) has been compromised by transgenic technology. The objective of this study was to compare two transgenic Bollgard (BG) and glyphosate tolerant (RR) cotton cultivars to their conventional parents for fiber properties, processing characteristics, and fabric quality. Field experiments were conducted with ‘Deltapine 458 BG/RR’ and ‘Deltapine 655 BG/RR’ and their recurrent parents, ‘Deltapine 5415’ and ‘Deltapine 5690’. These cultivars were planted at three planting dates (mid-April, early May, and mid-May) in 2000 and 2001. Ginned cotton was tested for fiber properties, processing waste, spinning performance, yarn characteristics, and white specks in dyed fabric. The transgenic and recurrent parent cultivars were not different in lint yield at any planting date in either year, and only small differences in HVI fiber properties occurred. Similarly, differences between the transgenic and recurrent parent cultivars for processing waste, spinning performance, yarn quality, and white specks were small, even when statistically significant. Differences between the transgenic and recurrent parent cultivars tended to be of the same magnitude or smaller than differences among planting dates. Late-planted cotton tended to have better yarn quality than early-planted cotton. The results indicate little difference in processing quality or efficiency between these transgenic cultivars and their recurrent parents.