Informal settlements are among the major problems that confronts many cities in the world. Despite numerousefforts both at the international and local levels to address this problem, its existence keeps on rising. This paperused a theoretical approach to assess the growth of informal settlements in Kumasi, Ghana. It adapted the theoryof Planned Behaviour with informal settlement dwellers been the target population. A total of 238 informalsettlement dwellers were covered with questionnaires serving as the research instruments. It was found out thatinformal settlement dwellers have bad behaviour towards such settlements and this was underpinned by their badintentions about informal settlements. Low awareness of building regulations and poor perception of land useplanning were the issues that influenced their behaviour through their intensions. The major contribution of thispaper is that the growth of informal settlements is to a greater extent orchestrated by bad behaviour towards suchsettlements and that policy makers and international bodies should have a second thought on these settlementsand pay keen attention to human behaviours towards informal settlements.Keywords: urban; housing; informal settlements; behaviour; Kumasi, Ghana