Despite industrial promotional measures of successive governments in Nigeria, minimal positive results have been achieved and the industrial sector remains under-developed and under-harnessed. One measure which will fasten industrial sector development is through cluster promotion hence the need for a comprehensive survey. This survey is expected to provide a useful insight into clusters in Nigeria focusing on the south-east and south-south geopolitical zones of the country with emphasis on identifying existing and potential industrial clusters in the two regions as well as major constraints inhibiting their operation. Survey findings reveal that the sectors with the highest number of existing clusters in the two geopolitical zones fall under agro-processing, followed by automobile, furniture and wood works, food, oil and gas, foundries, metals and fabrication. A list of their problems include: poor flow of information; infrastructure deficiencies; lack of adequate business networking; poor access to and supply of business development services; lack of articulated advocacy and engagement mechanisms; and skepticism about the feasibility and sustainability of joint actions.