We investigated a group of Australians, who lived in extreme poverty, by identifying early life and contemporary disadvantages associated with marginal housing or homelessness. Forty nine marginally housed and 51 homeless participants, who sought emergency relief from Melbourne charities, completed a 25 item questionnaire and a follow-up interview about their personal, social and material circumstances. Different combinations of early life and contemporary disadvantages predicted either marginal housing or homelessness. Receipt of disability benefits, vocational qualifications and post secondary education were uniquely and inversely associated with homelessness (positively associated with marginal housing). Being older, single and male were uniquely associated with homelessness. Level of housing insecurity among the poor was characterised by accumulation of early life and contemporary disadvantages, differentially predisposing individuals to marginal housing or homelessness.