Systematic calculations of the yrast superdeformed (SD) bands in (superscript 189-193)Tl nuclei using the projected shell model (PSM) are presented. The calculated △I=1 and △I=2 energy transitions, including the γ-ray energies, moment of inertia, and E(I)-E(I-1) transitions, are compared with the experimental data for which spins are assigned. Excellent agreement between the calculated results and available data indicates a microscopic understanding of those measured nuclei. The flattened J(superscript (2)) behavior of 192Tl and the signature splitting of (superscript 191,193)Tl are also discussed.