Provided are a photo-acoustic imaging apparatus and a method of displaying a photo-acoustic image by the photo-acoustic imaging apparatus. The method of displaying a photo-acoustic image by a photo-acoustic imaging apparatus includes: obtaining a first reception signal, which converts a first acoustic wave generated as light having a first wavelength is absorbed by a subject, and a second reception signal, which converts a second acoustic wave generated as light having a second wavelength is absorbed by the subject; determining a first correction coefficient for the first reception signal and a second correction coefficient for the second reception signal based on a ratio between a size of the first reception signal and that of the second reception signal; and displaying a photo-acoustic image which is corrected based on the first and second correction coefficients.