In addition to the classic roles that cyclic-3',5-guanosine monophosphate (cGMP) is thought to play in cell function regulation, such as smooth muscle regulation, inhibition of platelet aggregation, visual signal conduction and neutrophil degranulation, it is now understood to be involved with various physiological functions. The tissue levels and hence activity of cGMP are determined by the balance between production rates from guanosine triphosphate (GTP) through the guanylyl cyclase pathways, and degradation to GMP by specific cyclic nucleotide phosphodiesterases (PDEs). PDE5 inhibitors were initially developed for a possible role in cardiovascular disease; their role in the treatment of erectile dysfunction was brought to the forefront by the development of sildenafil. The focus of this article is the current patent literature around the use of PDE5 inhibitors for neuropathy. It also explores the possible hypotheses that may help to explain the mechanism(s) by which cGMP PDE5 inhibitors could have potential benefits in neuropathy.