For research purposes, it is often necessary to gin small cotton samples on laboratory-scale gin stands (lab gins) to evaluate fiber properties, but because lab gins differ from commercial gin plants, the validity of the results obtained has been questioned. The objective of this research was to compare fiber properties between cotton processed with lab gins and commercial gin stands. Seed cotton was collected at the gin stand feeder apron and lint was collected before and after lint cleaning at seven commercial cotton gin facilities. Each seed-cotton sample was subdivided for processing with four lab gins including two from Dennis Manufacturing, one from Continental Eagle Corporation, and one from Custom Fabricators and Repairs (CFR). Fiber properties of all lint samples were measured with the Advanced Fiber Information System (AFIS). Averaged over all commercial gin facilities, the CFR lab gin was found to cause more fiber breakage than the commercial gin stand resulting in a small reduction in fiber length and increase in short fiber content, but no differences were found for the other lab gins. Fineness data for the New Dennis lab gin was lower than the commercial gin stand. Immature fiber content was lower and maturity ratio higher than the commercial gin stand for the Old Dennis, CFR, and Continental lab gins. Neps were higher for the Old Dennis lab gin than the commercial gin stand, whereas seed-coat neps were higher for the CFR lab gin and lower for the New Dennis and Old Dennis lab gin. When these results were analyzed for all commercial gin facilities it was found that in most cases (except neps) differences between the lab gins and the commercial gin stands were not consistent from one gin facility to the next. This proved that results obtained from lab gins cannot be precisely reproduced, even with a correction factor, in commercial gin plants. Correlation analysis indicated that the New Dennis gin stand produced lint samples that were the most similar to commercial gin stand lint samples when considering all properties, and most correlations were strong for other lab gins as well. These results show that lab gins offer an effective, convenient screening tool for cotton researchers predicting fiber quality in commercial gins.