Anomalous signal fluctuations due to ionospheric scintillation at 1.5 GHz appear occasionally on earth-space paths in maritime satellite communication. With regard to the characteristics of ionospheric scintillations at gigahertz frequencies, few data are available in the middle latitude region. This paper describes the results of 1.5-GHz scintillation measurements at Yamaguchi, Japan. Measurements were carried out by receiving a 1.5-GHz beacon signal from the MARISAT satellite over the Indian Ocean with an elevation angle of 17.3°. In 13 months of measurements, very severe scintillation with peak-to-peak fluctuations exceeding 30 dB was observed in the equinoctial month, and a number of spike-type scintillations were also observed, particularly at night. Scintillation characteristics, such as diurnal and seasonal variations, amplitude distribution, spectrum, and depolarization are discussed.