AbstractDiet concordance and changes in dietary practices by surviving spouses of cancer cases were investigated by studying 69 husband‐wife pairs during an eight‐year period spanning the death from cancer of one spouse. The data base consisted of reports for each cancer case from the Adventist Health Study (AHS) where a surviving spouse was available. Two questions were addressed. 1. Do husbands and wives eat similar diets? 2. Did survivors change their diet practices during the eight‐year period? Three sets of dietary data were compared with the AHS food frequency questionnaire: reports made in 1976 by cases; reports made in 1976 by their spouses (initial); and the spouses’reports in 1984 (current). Diet concordance and dietary changes for 35 key food groups were evaluated both for individual foods and across foods by computing recall scores. The results were analyzed with univariate and multivariate methods. Comparison of means and Spearman rank‐order correlations revealed good initial concordance between the spouses, which was not significantly related to age, sex, or education. However, eight years later subsequent to the deaths of the cases, the agreement was poor because the surviving spouses had changed their diets. The changes in dietary practices were significantly related to education and body mass index in univariate analysis but not in analysis of covariance. These results indicate that retrospective recall by spouses for the cases rather than the spouses’own current reports should be used as an estimate for the deceased cases. Repeated recalls are necessary to increase reliability.