The SP-PLP-NIR technique, which combines Pulsed laser polymerization (PLP) initiated by a single pulse (SP) with time-resolved monitoring of the resulting monomer conversion via near-infrared (NIR) spectroscopy, was used to investigate the kinetics in aqueous solution of 2-acrylamido-2-methylpropanesulfonic acid (AMPS). For initial AMPS concentrations of 2.79 mol(.)L(-1) (50 wt% AMPS) and 1.04 mol(.)L(-1) (20 wt% AMPS), the ratio of (chain length averaged) termination and propagation rate coefficients, < k(t)>/k(p), was measured up to almost complete monomer conversion at temperatures between 10 and 40 degrees C and ambient pressure. Up to 80% monomer conversion, < k(t)>/k(p) is only slightly lowered, whereas there is a clear decrease upon further increasing conversion. Variation of temperature and of pH does not significantly affect < k(t)>/k(p). For estimating individual rate coefficients, < k(t)> and k(p), in addition chemically initiated polymerizations have been carried out, in which AMPS conversion was monitored via in-line FT-NIR spectroscopy. The resulting < k(t)> and k(p) values, for 40 degrees C and an initial AMPS concentration of 2.79 mol(.)L(-1), are 2 x 10(7) L(.)mol(-1.)s(-1) and 1 x 10(5) L(.)mol(-1.)s(-1), respectively. Both rate coefficients are significantly higher at the lower AMPS content of 1.04 mol(.)L(-1). < k(t)> at this lower AMPS content may be understood in terms of termination Occurring under reaction diffusion control. The lowering in rate coefficients measured at the higher AMPS content is indicative of a reduced poly(AMPS) chain mobility.