This paper focuses on the issue of surveying older people. Increasing interest in the issue of ageing and old age has been accompanied by infrequent debate on the methodological pitfalls that might influence research into this specific, albeit very heterogeneous population. Interviewers routinely complete post-interview questions that provide important information on such criteria as respondent difficulty in answering the questions posed. This article examines such difficulty in terms of interviewer and respondent characteristics. It investigates three potential explanations of why interviewers judge an interview as difficult: (1) interviewer characteristics (age and gender), (2) socio-demographic characteristics of the respondent and (3) respondents’ sense of well-being. The data used in this study were obtained from four surveys conducted with older people in the Czech Republic between 2007 and 2011. These surveys explored ageing and old age. The findings show the crucial importance of respondents’ sense of well-being and level of education. No interviewer age or gender effects were observed.