Se describe la evolución de las normas sísmicas en El Salvador, incluyendo un enfoque probabilística en la norma vigente. Se compara esta última norma con tres trabajos anteriores y se atribuyen las discrepancias a diferencias en cada paso de la estimación y no únicamente en las relaciones de atenuación. Se discuten las atenuaciones espectrales para América Central.The development of seismic building codes in El Salvador is described, including the incorporation of a probabilistic hazard study into the latest regulations. This hazard study is compared with three other assessments that over El Salvador, and it is shown that discrepancies arise from differences in each step of the hazard evaluation, leading to considerably divergent results. Although it may have been expected that the major uncertainy would result from the attenuation relationships employed, this review shows that definition of the seismicity model is also poorly controlled. Attenuation relationships for special ordinates in Central America are also discussed.