The evolved stellar content of Holmberg IX

V and I CCD images obtained with the Canada-France-Hawaii Telescope are used to investigate the evolved stellar content of the dwarf galaxy Holmberg IX (DDO 66). The number of evolved stars in this galaxy increases markedly at magnitudes fainter than I of about 21.5 and, assuming a distance modulus of 27.5, this is suggested to be a consequence of a decrease in the rate of star formation roughly 50 million yr ago. The luminosity function of asymptotic giant branch stars in Ho IX is in good agreement with that measured in the LMC, suggesting that the intermediate-age star-formation history of this Ho IX field is similar to that in the LMC. 25 refs