Mutual solubility data of water + pentan-1-ol and liquid liquid equilibrium of water + pentan-1-ol + 2,6,6-trimethylbicyclo [3.1.1]hep-2-ene (alpha-pinene) and water + pentan-1-ol + 6,6-dimethyl-2-methylenebicyclo[3.1.1]heptane (beta-pinene) have been measured experimentally at (293.15, 303.15, 313.15, and 323.15) K under atmospheric pressure. The estimated uncertainty of phase composition and temperature were about (0.0005 and 0.05) K, respectively. The experimental ternary liquid-liquid equilibrium data have been simultaneously predicted and correlated by the extended and modified UNIQUAC models.