Port Harcourt, one of Nigeria’s major cities has been experiencing rapid urbanization (of the order of 5% per annum on the average) since its founding by the British in 1913. The process of urbanisation is engulfing and transforming the way of life of the indigenous enclaves, which predate the founding of the city. This study has examined the impact of urbanization and its correlates on the socio-economic and socio-cultural aspects of life of the indigenes both subjectively (by questioning a probability sample of the indigenes) and objectively (from the judgment of experts using a state-of-the-art impact assessment methodology). The study found that while about one half of the respondents were pleased with urbanization, a little over one third were displeased with it. Reasons for pleasure included: development of the area, infrastructure development and improvement in aesthetics, while displeasure stemmed from increase in crime rate, destruction of traditional livelihoods, erosion of cultural values, among others. The study concluded that urbanization has indeed had both positive and negative impacts on the indigenous population and that there was reasonable agreement between subjective and objective impacts of urbanization. Finally, recommendations have been proffered to mitigate serious negative impacts including positive discrimination/affirmative action to help indigenes compete favourably with the usually more aggressive and better-equipped in-migrants.