The aims of this descriptive comparative study are to describe the levels of tsunami disaster preparedness of people living in areas affected and nonaffected by the December 2004 tsunami, and to compare the tsunami disaster preparedness of these two groups of people. A total of 304 subjects were recruited using a multistage-stratified random sampling from both of the areas along the west coast of Aceh Province. The Individual's Tsunami Preparedness Questionnaire was developed by the researcher and validated by three experts yielding a content validity index (CVI) of .95. Test-retest was performed with reliability coefficients for knowledge, individual emergency planning, and resource mobilization capacity of .99, 1, and .99, respectively. The Individual's Tsunami Preparedness Questionnaire was used to measure the subjects' knowledge, individual emergency planning, and resource mobilization capacity related to tsunami preparedness. The findings showed a moderate level of tsunami preparedness of people living in both areas including the variables that cover knowledge, individual emergency planning, and resources mobilization capacity. The mean scores for each variable of people living in affected areas were significantly higher than people living in non-affected areas (p <.05). Sub-variables were also at higher mean scores except one of the sub-variables, individual emergency planning: "skills related to disaster preparedness", that was at a lower mean score. This study provided evidence that direct experience for the people living in affected area and indirect tsunami experience for the people living in non-affected area has a significant impact on people's tsunami preparedness.