Following the Loma Prieta earthquake, a study was initiated to evaluate the liquefaction potential of fill soils in San Francisco. Field investigations were conducted at several sites along the San Francisco waterfront where pre-earthquake data were available and/or the field performance during the 1989 event was well documented. Based upon the interpretation of cone penetration test data, several areas underlain by zones of dune sand present in the fills appear to have densified when compared to pre-earthquake data. These fill sands were in a loose-to-medium dense state prior to the 1989 earthquake. Although several steps of the interpretation require assumptions at this stage of the research project, the liquefaction assessments made for Loma Prieta type conditions correlate well with the observed performance of the different sites. It is shown that a number of locations would suffer severe damage during a postulated magnitude 7.5 event occurring close to San Francisco, and many sites would be affected to a lesser degree. Even engineered fills may suffer some level of distress because of zones of looser material at shallow depths.