Eucalyptus is an important plant grown in cities in Cameroon because they perform specific functions such as draining of wetlands to increase available land area for housing construction to accommodate the bourgeoning urban population. To investigate the changing patterns of eucalyptus plants in Bali sub-division and its implications towards sustainable city planning in Cameroon, a blend of information collected from published and primary sources were used. Analysis of collected information was done with the help of cartographic and descriptive techniques including maps, tables and percentage and cumulative percentages. The results showed that the eucalyptus population in Bali sub-division has significantly evolved over time and space from 3.39km2 in 1990 to 9.47km2 in 2017. There is a significant decline in the zone occupied by the plant from mostly the urban or build-up area between 1950 and 1990 to mostly peri-urban and rural areas in 2017 due mainly to accelerated urbanisation, rapid population growth and counter-migration to rural areas to seek large farm sizes for eucalyptus cultivation. These are indicators that favour medium and long term sustainable planning policies by city and town planners towards attaining sustainable cities in Cameroon through the relocation of saw mills from urban to peri-urban and rural areas thereby preventing noise and sound pollution in cities; reduce damage to buildings and other urban infrastructures by the long spreading roots of the eucalyptus plants; rehabilitate watersheds and put in place appropriate municipal water management plans to increase water supply in cities and the planting of shade and other multi-purpose tree species in the place of the declining eucalyptus population in order to help reduce overheating, provide greening, urban aesthetics and municipal parks and botanic gardens.