A photoacoustic imaging apparatus (100) includes a light source portion (21) and a signal processing portion (30). The signal processing portion is configured to perform imaging processing on the basis of at least either a first acoustic wave signal (70a) corresponding to a rising edge (90a) of a pulse signal (90) of pulsed light or a second acoustic wave signal (70b) corresponding to a falling edge (90b) of the pulse signal of the pulsed light.