Ultrasound continues to be one of the major imaging modalities used for the diagnosis and treatment of a number of medical conditions. Therefore emphasis on innovation is continually increasing the quality of the ultrasound systems. However focus is just beginning to shift into the low-cost and portable applications of ultrasound. These systems present interesting constraints which must be considered to transform a standalone system into a portable version. This review takes a look at some of the attempts which have been published, as well as some of the issues which have still yet to be resolved. In conclusion, low-cost portable ultrasound has the capability to be developed and commercialized, but until a suitable replacement to piezoelectric crystals has been developed (possibly CMUTs?) low-cost portable ultrasound system will be held back by the high cost burden associated with the cost of piezoceramics.