The evaporation and condensation coefficients of water are extensively analyzed considering also data hitherto not taken into account. From the performed evaluation, a decline of both coefficients with increasing temperature and pressure is derived. For water, the condensation coefficients is generally higher than the evaporation coefficient. Evaporation and condensation coefficients exceed 0.1 for dynamically renewing water surfaces, while the analysis reveals coefficients below 0.1 for stagnant surfaces. The influence of impurities and surface active substances, as well as the effect of the dynamic surface tension is discussed.