Centre for Longitudinal Study Information and User Support (CeLSIUS) exists to assist people in UK higher education to analyse the Office for National Statistics Longitudinal Study (ONS LS). CeLSIUS is part of the Economic and Social Research Council's (ESRC) Census Programme for 2006-2011. Part of the service it offers is the provision of web-based tools and extracts, including the subset of the ONS LS. Further information about CeLSIUS is available from the CeLSIUS web site and the ESRC Award web page. Limiting Long-Term Illness: Longitudinal Perspectives, 1971-2006 is an aggregated teaching dataset which has 367 records (i.e. combinations of values of the variables). It is based on 314,493 cases; cases are ONS LS sample members who:were enumerated at both of the most recent censuses (1991 and 2001) reported that they were without a limiting long-term illness (LLTI) in 1991gave a valid response on whether they had a LLTI in 2001were aged 20 years or more in 2001The ONS LS sample provides a random, one per cent sample of the population of England and Wales, clustered by date of birth. The documentation includes exercises to accompany the dataset with instructions for both SPSS and Stata users. Exercises centre on exploring the dataset by age, gender, activity status, whether respondent has a partner and whether the respondent has a LLTI. The dataset includes the following eight variables:genderage group in 2001whether has partner in 1991whether has partner in 2001economic activity status in 1991economic activity status in 2001whether has LLTI in 2001weight variable