The seakeeping performance of passenger vessels is generally assessed by using a procedure based on the probability of exceeding specified ship responses in a sea environment particular to the ship's route. The percentage of time the responses are below specified limits in a particular sea state can be determined from an oceanographic database through application of the response amplitude operators. However, this procedure is strongly affected by the chosen limiting criteria. This is particularly the case for passenger vessels where many conflicting criteria are used to assess the effect of motions and accelerations on comfort and well-being of passengers. This paper investigates the effect of seakeeping criteria on habitability performance assessment for passenger vessels. Conventional seakeeping performance measures are evaluated for various levels of vertical accelerations defined by the ISO 2631 standard. It is shown that the estimated habitability performance of a passenger vessel greatly depends on the level of limiting value selected as the seakeeping criteria.