The aim of this article is to examine a number of aspects of uncertainty faced by poverty-stricken residents in the western Polish city of Poznań from the perspective of their incomes, work and prospects for the future. The methodology and the concept behind this research both stem from the activities of “The Underclass of Poznań” Cross-Community Research Group, which conducted a number of paper-and-pencil interviews in 2012 and 2013 in order to collect detailed answers from respondents and a set of qualitative data. A random sample of beneficiaries of Poznań’s Municipal Family Support Center (MFSC) was selected in two measurement stages (n1=418, n2=196) from a total of 6,000 addresses. The selected sample size guarantees that, with 95% probability, the obtained research results do not differ from the distributions of the variables in the overall statistical population by more than 4%. The article includes an analysis of the notion of uncertainty from a socioeconomic angle, and it also lists the links between certainty and security. It has been stressed that income constitutes the primary factor influencing security, with respect to both its volume and the certainty of its receipt. It has also been noted that women receive higher incomes than men, which distinguishes this research from other research findings. In general, it needs to be emphasized that income levels are relatively low in all income groups, which results from the specific features of the studied population, whose members are all beneficiaries of social welfare programs. Needs deprivation in the analyzed population does not merely result from low incomes, but also reflects the lower level of need awareness in comparison with other social groups. The respondents’ general feeling of economic uncertainty is also affected by the range of available opportunities and the degree of need satisfaction. Incomes earned by the studied population are only sufficient for households to afford the cheapest food and, sometimes, clothes and to pay for basic accommodation. Apart from income uncertainty, this paper focuses on threats to job security because, in spite of their relatively high job insecurity, respondents tend to adopt passive attitudes on the job market, with a low overall level of activity and failure to actively look for employment. The respondents’ uncertainty of the future is a consequence of their uncertain incomes and unemployment, factors that can be viewed as either intrinsic or extrinsic.