This study examined the extent and type of spatial market integration in fish marketing in Nigeria. It used private traders' monthly retail prices in spatially separated markets. The empirical analysis revealed the markets that recorded the highest mean monthly prices. Variability index showed that fish prices fluctuated widely. The price of a kilogramme of dry fish compared with same weight of fresh fish revealed that cost of marketing functions and marketing margins were high. Both fresh and dry fish markets exhibited strong price consonance. The long-run market integration model revealed that 40.90% and 59.09% of fresh and dry fish market pairs had prices which were cointegrated. Evidence of price leadership in fresh fish price formation and transmission occurred in Kano, Bauchi, and Makurdi ( 0.05). In dry fish marketing, Kano, Akure and Makurdi were the price leaders. Fresh fish markets were less competitive and less efficient compared with dry fish markets. It is recommended that government improves fish price information dissemination through decisive policies and programmes.