Expressions are derived which describe the relaxation rates of spin systems under multiple-pulse conditions where the randomly fluctuating interaction is the chemical-shift Hamiltonian. The multiple-pulse schemes include the REV-8 pulse cycle and two “chemical-shift-concertina” cycles. One of these is the phase-alternated sequence, and the other is a new cycle consisting of four π pulses which more effectively suppresses lineshape artifacts resulting from rf inhomogeneity and other pulse imperfections. The calculated relaxation rates are used to predict lineshapes of chemical-shift spectra obtained from multiple-pulse experiments. A general discussion is presented in which T 1 and T 2 types of relaxations, anomalous T 2 behavior when the correlation time is comparable to the cycle time, and chemical-shift scaling factors are related in a simple physical description. The theoretical predictions are shown to agree with experimental results obtained in the chemically exchanging liquid system of PF 3Br 2. These experiments include temperature-dependent lineshapes obtained by Fourier transform NMR, REV-8, and four-π pulse chemical-shift concertina (scaling factor, 0.18), as well as REV-8 relaxation times.