The present study delves to analyze the difference of company financial performance prior to and after acquisition in companies listed in the Indonesian Stock Exchange. The financial performance is measured by involving seven financial ratios: current ratio (CR), total asset turnover ratio (TATO), debt to equity ratio (DER), net profit margin (NPM), return on assets (ROA), return on equity (ROE), and earning per share (EPS). The comparative quantitative study involved the population of seven companies listed in the Indonesian Stock Exchange that conducted acquisition activity during the period of 2012-2018. From the population, five companies were acquired as the samples by purposive sampling technique. The study employed normality data test and Wilcoxon signed rank test as the data analysis techniques. The results showed that four financial ratios, i.e., current ratio (CR), debt to equity ratio (DER), net profit margin (NPM), and earning per share (EPS) are not significantly different prior to and after the acquisition. On the other hand, the ratios of total asset turnover ratio (TATO), return on assets (ROA) dan return on equity (ROE) yield negative significant result before and after acquisition. Therefore, the paper concludes that acquisition impacts negatively to the company financial performance.