Esq echo intensities recorded by a dynasonde system operated at Huancayo, Peru, are used to estimate the scattering cross section of equatorial electrojet plasma irregularities in the 3 to 7 MHz frequency band. The scattering radar cross section of vertically propagating ~20-m scale electrojet irregularities is estimated as ~3¿10-7 m-1 over a period exhibiting foE values of 2.7 to 2.9 MHz. The cross-section variation with Bragg wavenumber k is found to be characterized with a power law index of approximately -3 over the HF band.