This study first identifies the poor and then investigates their self-assessment. As previous studies have argued that the compositions of the poor are quite different according to the use of income and/or deprivation as indicators to define the poor, and furthermore a pilot survey in this study confirmed that the argument could be true of the Korean situation, this study classifies the poor into three groups: the income poor whose income is lower than the 2005 Korean government poverty line; the deprivation poor whose deprivation scores are higher than a deprivation poverty line; and the consistently poor who belong to the income and the deprivation poor at the same time. After the poor are defined, self-assessment of the three poor groups is explored and compared in terms of two aspects: what is self-assessment of the poor; and which variables have an impact on their self-assessment. In order to explore self-assessment of the poor, this study uses a data set, which was obtained by the 2004 official survey specially designed and conducted by the Korea Institute for Health and Social Affairs for the 2005 Korean government poverty line. The data set has the advantage that it is the largest and latest one in measuring poverty in Korea. However, in relation to this study, there was a critical problem with the data set that it was not intended to measure self-assessment of the Korean households, which is essential to this study. Thus, for this study, some questions, which I developed to deal with the measurement of self-assessment, were required to be inserted into the original survey questionnaire, but due to practical limitations one of them was included in the questionnaire. The analysis of the data set shows that the income poor are matched with the deprivation poor at only 50%, which confirms that the poor are quite differently identified when income and/or deprivation are used as indicators. In addition, it is found that poverty status by self-assessment is quite different from that by income and/or deprivation, and that the influential impact of variables on self-assessment varies according to the poor groups.