Illegal wildlife trade presents a serious threat to the long-term survival of certain species, which can have serious ecological and socio-economic consequences. Officials attempting to enforce wildlife trade legislation are often hampered by difficulties associated with the accurate identification of such items. In response, this thesis describes the development and application of molecular tools for the analysis of animal parts and derivatives, with reference to two main contemporary issues; namely, the illegal trade in bear (Ursid) parts and derivatives, and the illegal trade in rhinoceros parts and derivatives. A qualitative lateral flow immunoassay (LFIA) dipstick was developed for bear serum albumin detection. The visual detection limit was 10 ppm of bear serum with a reaction time of 5 min. The LFIA was validated on serum, blood, skin and liquid bile, and was able to detect bear albumin in all these sample types. Items confiscated during enforcement activities were also tested and the results confirmed by DNA sequence analysis. PCR primers were designed such that DNA from ursine species could be amplified from samples containing mixed-species DNA. The VIA accurately identified genuine bear bile crystals and bear bile capsules, although it was unable to consistently identify bear bone and some of the more complex traditional Asian medicines (TAM). The test can be performed by persons with little or no scientific training and may provide a novel method for customs and law enforcement officials to screen purported bear bile samples and gallbladders in the field. The feasibility of using mitochondrial and nuclear DNA for individual identification in the white rhinoceros, Ceratotherium simum, was assessed. A molecular method for sexing rhinoceros samples was developed and incorporated into a short tandem repeat (STR) profiling assay. which was then partially-validated for forensic use and used to screen various rhinoceros sample types (horn, blood, tissue) from wild and captive white rhinoceros. The recovery of nuclear DNA (microsatellites) from rhinoceros horn is demonstrated, opening up the possibility of being able to match confiscated horn samples to a particular rhino carcass. A preliminary assessment of the authenticity of exotic meat products sold in the UK was performed. and 40% of items were found to be fraudulent. The implications of this finding are discussed, and the study highlights some of the difficulties associated wth mitochondrial DNA-based species identification.