A study was conducted to assess the relative performance of different flexible pavement maintenance treatments, including the influence of pretreatment condition and other factors. The data used in the study were drawn from the Long-Term Pavement Performance Studies' Specific Pavement Studies (SPS) SPS-3 experiment. The maintenance treatments used in the SPS-3 experiment are thin overlays, slurry seals, crack seals, and chip seals. The initial and long-term effects of the maintenance treatments on international roughness index (IRI), rutting, and cracking were analyzed, as were the influences of time, truck traffic, pretreatment condition, and climate. Thin overlays were found to be the most effective of the treatments studied, followed by chip seals and slurry seals. Crack sealing did not demonstrate any beneficial initial or long-term effect with respect to IRI, rutting, or cracking.