The results of this study are subject to several important limitations. We used a case definition that required self-report or report by a proxy of an illness that occurred up to one year prior to interview. It is well known that such self-reports are limited by recall decay, and recent episodes are more likely to be recalled than earlier episodes. [21] This could be noted in our data that demonstrated a decreasing report of pneumonia with increasing time before the survey. As long as recent illness episodes do not differ from prior episodes with regard to patterns of healthcare-seeking behaviors, there is no reason to believe that recall decay causes bias with regard to these variables. Because our case definition is based on self-report, there is substantial potential for misclassification, especially between mild and severe acute respiratory illness, and this can be seen in the report of some lower respiratory tract symptoms among respondents with ILI. However, the behaviors associated with episodes of ILI compared to pneumonia (lower probability of seeking care outside the home, less likely to seek treatment at a hospital) are suggestive of a more mild illness and we are reasonably confident that we have described the healthcare seeking behaviors that are broadly associated with both pneumonia and ILI. An additional limitation is our sample size, which is too small to permit age to be stratified into more than two groups, restricting our ability to model healthcare-seeking behaviors more precisely by smaller age groups. Finally, it is not clear whether results from one area of Guatemala with a significantly lower indigenous population than the rest of the country can be generalized to the nation as a whole.