Pararosaniline acetate is used as a histological stain to visualize cellular structures under the microscope, particularly in demonstrating mitochondria, glycogen, and bacteria in tissue samples and microbiological media. It also serves as a pH indicator in analytical chemistry due to its color change in different acidity environments. In the textile and leather industries, it acts as a dye providing durable red or purple-red colors, suitable for natural materials such as cotton and silk. Additionally, it is employed as an intermediate in the production of other dyes and in quality control tests for evaluating filter efficiency and tracing studies in environmental systems.