In the past decade, there has been increasing attention paid to the recycling of cotton fabric waste. In the present study, different concentrations of sodium hydroxide (NaOH) ranging from 1 M to 4 M were used to thermomechanically deweave cotton fabric. The fabrics treated with 1 M NaOH and 2 M NaOH were partially deweaved, whereas those treated with 3 M NaOH and 4 M NaOH were completely deweaved. Fourier-transform infrared (FTIR) spectroscopy was applied to analyze the chemistry and structure of the cotton fabric. The FTIR spectra indicated that the structure of cotton fabrics treated with 1–2 M NaOH were similar to that of pristine fabric, while the presence of NaOH was observed. In the case of samples treated with 3–4 M NaOH, both the peak positions and the band intensities were changed, in addition to the formation of cellulose II. FTIR spectra for the recycled NaOH-treated cotton fabrics were compared, and no major structural changes were identified. A post-treatment with deionized (DI) water removed excess Na+ ions, with the sample showing a similar molecular structure to that of the pristine material. These results suggest the feasibility of recycling aqueous NaOH for post-washing treatment as a new method for recycling cellulosic fabric waste.