The present invention provides a method for detecting and locating brachytherapy seeds using Singular Spectrum Analysis (SSA). The method exploits the presence of seed-specific repetitive echo signals in detecting seeds and determining their location. Radio frequency (rf) echo signals received from a scanned area of interest are converted to zero-mean envelope-detected signals and then processed using SSA to produce a spectral-power line (a P line). The P line indicates the relative likelihood of a seed being present. A colored P-mode image derived from a set of P lines is superimposed on a conventional ultrasound B-mode image to depict seed location.