Self-organized quantum dots are being incorporated in the active regions of interband lasers, modulators, and infrared detectors and sources. The unique hot-carrier relaxation rates in quantum dots play an important role in defining the device characteristics. We have conducted extensive theoretical and experimental studies of carrier dynamics in In(Ga)As/Ga(Al)As self-organized quantum dots grown by molecular beam epitaxy. Experimental techniques used include small and large-signal modulation of lasers and femtosecond pump-probe spectroscopy. It is found that the intersubband electron relaxation rates, which are strongly temperature dependent, are determined by electron-hole scattering in the dots. Theoretical calculations also show that electron-hole scattering is the dominant mechanism for the relaxation of hot carriers. It is also found that a phonon bottleneck exists in the dots for very weak excitations. The implications of these results on device performance will be discussed.