The first in vitro evidence that highly nanostructured silicon could be a biocompatible material was published in 1995. This review summarizes some of the procedures, challenges and progress made by pSiMedica Ltd, UK (pSividaCorp.USA) and others over the period 2000–12 in progressing from early-stage research to clinical assessment of porous silicon in the fields of brachytherapy and pre-clinical work for drug delivery.