Multifunctional carboxylic acids have been used as nonformaldehyde durable press finishing agents for cotton. In previous research we found that maleic acid (MA) and itaconic acid (IA) polymerize in situ on cotton fabric at elevated temperatures when both potassium persulfate (K2S2O8) and sodium hypophosphite (NaH2PO2) are present, thus imparting wrinkle resistance to the treated cotton fabric. We also found that MA and IA polymerize in aqueous solutions in the presence of K2S2O8 and NaH2PO2. In this research, we compared the effectiveness of poly(itaconic acid) (PIA) applied to cotton fabric as a polymer and IA applied as a monomer and allowed to polymerize in situ for crosslinking cotton cellulose. We found that IA is more effective in esterifying cotton cellulose and imparting a high level of wrinkle resistance to the fabric as it polymerizes in situ than PLA applied as a polymer. We also found that tensile strength loss of the cotton fabric crosslinked by IA polymerizing in situ as a function of fabric wrinkle recovery angle is practically the same as that crosslinked by PIA applied as a polymer.