We investigated conservation status, biodiversity potentials and economic contribution of urban tree Ecosystems in Nigerian cities. A total of 32 families were encountered respectively in Makurdi (17), Ilorin (18) and Lokoja (25) urban forests. The diversity index, richness and evenness of the tree species were in the order Ilorin > Lokoja > Makurdi urban forests and decreased as the population of the city increased, suggesting that the urban forests and trees depends on city infrastructure development. About 32% of tree species in the three cities are threatened tree species in Nigeria and based on the IUCN red list. This situation therefore calls for urgent conservation measures. Moreover, results showed a general increasing trend in Normalized Different Vegetation Index (NDVI) value between year 2000 and 2018 for the vegetation cover in each city. The NDVI value for Makurdi was (0.23 to 0.37), Ilorin (0.42 to 0.47), and Lokoja (0.01 to 0.27), which was very low compared to forest cover NDVI. The NDVI could be used to observe the changes in vegetation greenness and the dynamic effects of temperature. The average monthly income obtained by those involved in the sales of urban tree products such as (vegetables, fruits, recreation parks, event centers, and amusement parks) ₦20,000 (56 USD) to over ₦50,000 (139 USD) contributed between 40 and 70% to household annual income. This was particularly important in augmenting income from other sources in meeting basic family expenses in the cities.