With the rapid expansion of nanoscience and nanotechnology in interdisciplinary fields, multifunctional nanomaterials have attracted particular attention. Recent advances in nanotherapeutics for cancer applications provided diverse groups of synthetic particles with defined cellular and biological functions. The advance of nanotechnology significantly increased the number of possibilities for the construction of diverse biological tools. Such materials are destined to be of great importance because of the opportunity to combine the biotechnological potential of nanoparticles together with the recognition, sensitivity and modulation of cellular pathways or genes when applied to living organisms. In this mini review three main types of Si-based nanomaterials are highlighted in the area of their application for therapy and imaging: porous silicon nanoparticles (pSiNPs), mesoporous silica nanoparticles (MSNs), focusing on their nanoconstructs containing coordination compounds, and periodic mesoporous silica nanoparticles (PMONPs). Moreover, a critical discussion on the research efforts in the construction of nanotheranostics is presented.