Co-ordinated efforts to collect and maintain cotton genetic resources have increased over the last 100 years to insure the worldwide economic value of cotton fibre and cotton by-products. The classified genetic resources of cotton are extensive and include five tetraploid species in the primary gene pool, 20 diploid species in the secondary gene pool, and 25 diploid species in the tertiary gene pool. There are at least eight major cotton collections worldwide and their status and contents are discussed. An overview of the collections suggest that there is a substantial coverage of the Gossypium genome but some recently identified species are not yet maintained and several species are underrepresented and threatened by loss of their natural habitat. Meeting the high demand for cotton genetic resources and increasing the coverage of the genus with decreasing budgets are a few of the challenges facing individual collections. These types of challenges and the opportunities for international collaboration that they create are discussed. One desirable outcome of co-ordinated efforts among collections would be finding gaps in the collections and sharing of the workload to conserve the genus. Multinational communication and collaboration are critical for the evaluation of rare and unique cotton germplasm and protection of the global cotton germplasm resources.