In this study experimental liquid-liquid equilibrium data are reported for the systems water + epsilon-caprolactam + 1-heptanol, and water + epsilon-caprolactam + 1-heptanol + ammonium sulfate at 20 degrees C, 40 degrees C, and 60 degrees C. It is shown that with increasing temperature, the solubility of epsilon-caprolactam in the organic phase increases to a greater extent than the solubility of epsilon-caprolactam in the aqueous phase. An increasing salt concentration in the aqueous phase results in a salting out of epsilon-caprolactam into the organic phase.