Little is known about the molecular mechanisms involved in cocaine addiction. An understanding of the mechanism at the level of protein expression would be potentially useful for coming up with a treatment. This study analyzed the proteins from brains of cocaine treated (dose of 20 milligrams per kilogram of body weight) and control (treated with saline) BALB/cByJ mice using a proteomics based approach. The proteins were digested with trypsin and analyzed using Liquid Chromatography - Tandem Mass Spectrometry (LC-MS/MS) followed by identification and quantitation using the MASCOT protein database search engine. The proteins were then functionally classified using PANTHER. The cocaine treated mouse brain showed a significant increase in energy, metabolic and transport related proteins consistent with increased cell activity. Also, a protein, myelin basic protein (MBP), was found to be increased in the cocaine treated brain similar to a peptidomics study by Rhodes and Sweedler (2015) performed on the same brains that looked at neuropeptides that were derived from MBP that are involved in the reward pathway that is implicated in the addiction process. This implies that the mechanism of cocaine's effects is at the level of protein expression rather than at the processing step of the protein to neuropeptides.