This paper describes a study of excited-state properties of naphthalmide (NI) and four 4-substituted derivatives: 4-chloronaphthalimide (Cl-NI), 4-methylthionaphthalmide (MeS-NI), 4-nitronaphthalimide (O2N-NI), and 4-(N,N-dimethylaminonaphthalimide (Me2N-NI). Steady-state absorption and fluorescence spectra were collected in solvents of varying polarity to determine the excited-state character of NI derivatives. Furthermore. the excited-state dynamics were studied Using femtosecond transient absorption spectroscopy. The experimental findings were compared to calculated data obtained using time-dependent density functional (TD-DFT) methods. We found that light absorption by all NI derivatives leads to the production of the second excited state (S-2), which was found to have a n,pi* character. Within similar to 40 ps, the S-2 state undergoes internal conversion to produce the S-1 state. The S-1 state is relatively long-lived (similar to 4 ns) and has charge-transfer character in NI derivatives with electron-withdrawing and electron-donating groups (MeS-NI, O2N-Ni, and Me2N-NI). In the case of NI and Cl-NI, the S-1 state has a pi,pi* character and undergoes intersystem crossing to produce the T-1 state within 400 ps.