A biological information processing device includes an image input unit that inputs image data, a selection unit, an estimation unit, a detection unit, and an output unit. The selection unit selects image ranges of processing targets from the input image data. The estimation unit estimates pulse rates of the processing targets corresponding to the image ranges on the basis of image data of the selected image ranges of the processing targets. The detection unit performs relative comparison between the estimated pulse rates of the processing targets and thus detects a target which will possibly be abnormal or a target requiring special attention. The output unit outputs information regarding the detected target which will possibly be abnormal or the detected target requiring special attention.