In the assessment of the seismic hazard of buildings, several methodologies have been proposed based on the capacity curve obtained via Pushover Analysis. On the other hand, the Incremental Dynamic Analysis is a powerful tool analogue to the pushover analysis because the input is increased and the maximum response of the structure is obtained in each increment. Therefore, it is important to compare the results obtained with these methodologies. On the other hand, the uncertainty associated to the structural behavior, because mechanical properties are random variables, and the uncertainty of the seismic hazard, is another important aspect that must be considered. In order to include this probabilistic approach, Monte Carlo simulation is applied to study the stochastic response of a building model. Besides, the seismic hazard is defined as a random variable taking several registers of acceleration compatible with acceleration response spectrum given for a zone. The results obtained from static and dynamic analyses are finally compared and discussed from a probabilistic point of view. This probabilistic analysis shows that the spread of the fragility curves increases with the damage state, thus rendering highly uncertain the curves obtained by probabilistic approaches.