This chapter endeavours to illustrate the existing system of day fines in Polish criminal law. After historical overview of the rationale and circumstances for transforming to day fines and the further evolution of day fine model adopted in Poland, the study analyses the goals and objectives assigned to the current pecuniary sentencing system. The authors then examine the Polish legal framework on day fines: the study covers the rules provided for by the Criminal Code and by complementary legislation, in order to point out the provisions that could be perceived as essential of the new fine model, such as: the rules for setting the fine, the authorities imposing it and the manner in which this penalty is to be enforced. The broader aim of this chapter is to demonstrate the lights and shadows of the day fines practical side, as well to participate in the discussion about the significance of day fines in the contemporary criminal sentencing system. In this respect, the study highlights certain disconcerting symptoms in the field of factual relevance of the day fine in Poland, in relation to the other sanctions. The final part focuses on the insights regarding the perception of fine by Polish society.