Ages of adult goldeyesHiodon alosoidescollected in 1987 from the Peace–Athabasca delta, northeastern Alberta, were determined from scales and opercula. Mean ages estimated from scales (N= 114) and opercula (N= 117) were 8.5 and 14.8 years, respectively, and the maximum age discrepancy for a single fish was 10 years. The 1971 year-class, dominant and abundant during the 1970s, was used to assess general accuracy of the two age determination methods. The 1971 year-class represented 25% of the 1987 catch of adult goldeyes by the operculum method, but was not recorded by the scale method. This suggests that opercula provided accurate (correct) estimates of age for many of the adult goldeyes.