The photo catalytic degradation of a common analgesic (acetaminophen) with titanium dioxide irradiated with low energy ultraviolet light (365 nm) was studied in order to determine the effect of several parameters such as catalyst’s weight, photochemical effect, and initial concentration. The results indicate that acetaminophen is degraded in the order of 4% by the photochemical effect. The presence of titanium dioxide in optimal amounts increases the rate of reaction and the overall conversion. The kinetic study demonstrated that photo catalytic degradation of acetaminophen follows a pseudo first order reaction rate which could be represented by a model similar to Langmuir-Hinshelwood equation. Accordingly, the results confirmed that the degradation of acetaminophen proceeds even while other intermediate organic products (IOP) are being formed; some of these organic products were identified by High Performance Liquid Chromatography (HPLC). These products (OIP) remain in the solution for a while before being degraded to CO2. Furthermore, the experimental results indicate that the mineralization of acetaminophen can be described by an overall kinetic rate equation obtained from the experimental values of total organic carbon (TOC).