If respondents recognize repeated survey questions and remember their previous responses, this can result in measurement error. Most studies to date that have investigated respondents’ recall of their prior answers have done so in the context of repeated measurements within one cross-sectional survey. The present study extends this research to a longitudinal panel context by investigating whether respondents remember their previous responses to different types of survey questions (beliefs, attitudes, and behaviors) from a previous wave in a probability-based online panel in Germany. We find evidence that some respondents remember their responses from a previous panel wave even after four months, but at a considerably lower rate than previous studies found within a single cross-sectional survey. Respondents who could not remember their response were most commonly off by only a single scale point. Respondents remembered their responses to different types of questions at different rates and were more likely remember an extreme response. Female respondents were more likely to remember their responses, but we find no link to age, education, perceived response burden, survey enjoyment or online panel experience. As respondents could not remember their previous responses in most cases and we find little evidence for a systematic variation of memory effects across groups of respondents, we conclude that the potential for measurement error due to memory effects across panel waves is low after four or more than four months.