The aim of this study is to determine if high feed sliver moisture content will improve spinnability in rotor spinning without deteriorating yarn properties. Yarns are produced at a high rotor speed and low twist level. Two different count rotor spun yarns (18's and 24's) are spun from 100% cotton sliver at two different feed sliver moisture contents and two different opening roller speeds. Results indicate that high moisture content reduces the number of ends down, but increases yarn unevenness and the frequency of thin places, thick places, and neps. In addition, yarn elongation and work-to-break results are worse at high moisture content during spinning. In the case of fine yarn, a high opening roller speed tends to improve spinnability by reducing the number of ends down. Yarn evenness and thin and thick place results are also better. Overall, the results suggest that feed slivers with high moisture content can provide better spinning performance in rotor spinning. In other words, high moisture content can increase the production rate of open-end rotors, thus reducing the production cost of rotor spun yarns. However, a high moisture content also tends to deteriorate yarn evenness, increase the frequency of imperfections, and decrease yarn elongation.