The location of Lima city and El Callao in the Pacific coast and the long history of seismic activity were the main reasons to develop a seismic microzoning map. The microzoning study was based on large numbers of geotechnical and geophysical exploration points distributed around the study area. The geotechnical exploration consisted of borehole tests and pits, from which soil samples were taken to the laboratory to determine the soil mechanical characteristics. The geophysical exploration consisted of onepoint microtremor measurements and various methods to estimate the S-wave velocity profile. The results of both, the geotechnical and geophysical exploration were combined to develop a seismic microzoning map for Lima city and El Callao. This map shows five zones, where the zone with the best soil mechanical and dynamic characteristics covers most of the study area.