Analysis of molecular and medical images is an important area of interdisciplinary research. Accurate interpretation and understanding of those images is increasingly demanding because it opens doors to accurate diagnoses of diseases and novel biomedical discovery. During the image collection, imaging devices are quite often interfered by various noise sources. Impulse noise degrades biomedical image details such as edges, contours and texture. In this paper we present a robust technique for filtering impulse-noise degraded biomedical images. The proposed filter is based on noise detector and cubic interpolation. Experimental results on several types of biomedical images and comparisons with several existing noise-filtering models have demonstrated that not only the proposed filter is effective for noise removal but also for image detail preservation.