We estimate seasonal oligopoly power at a disaggregated variety level in the D'Anjou pear market. Our data spans 1993 to 2000, during which time imported pears became more prevalent in the U.S. market. The range of monthly industry-conduct-parameter magnitudes is 0.034 to 0.195 and is most pronounced when the fresh D'Anjou pear crop first becomes available in the earliest months of the marketing year. Possible reasons for timing of oligopoly power relate to the growth of imported pears during the latter portion of marketing year. In addition, oligopoly power may diminish during the marketing year as pears in storage decline in quality.