On the basis of picosecond fluorescence lifetime measurements, we report the fluorescence quenching dynamics of azulene and 2-haloazulenes (halogen = Cl, Br, and I) in cyclohexane by CCl4 in the S-2 electronic state. It has been observed that azulene fluorescence is efficiently quenched by carbon tetrachloride with a diffusion-limited rate constant of 8.1 X 10(9) M-1 s(-1), while 2-haloazulenes do not show fluorescence quenching by CCl4.