Nucleic acid detection in point-of-care settings would bring tremendous benefits to early diagnosis. Colorimetric nanoprobes have proved to be promising for point-of-care testing (POCT) thanks to their simple result readout (qualitative visual and/or quantitative transmittance/absorbance readout). In this chapter, two types of colorimetric nanoprobes (i.e., gold nanoparticles and enzyme mimetics) for nucleic acid testing are introduced. To realize highly sensitive detection, some of these colorimetric assays have been coupled with nucleic acid amplification, which can be classified into thermocycling and isothermal amplification reactions. Current challenges for widespread applications of point-of-care nucleic acid testing are discussed.