Surface-enhanced Raman Spectroscopy (SERS) is a unique technique that allows us to detect samples in trace quantities. This nanomaterial assisted phenomenon has been extensively studied over past several decades for sensing various chemical, biological and gaseous samples. Present work demonstrates the working of a paper-based SERS substrate to detect and quantify two pharmaceutical drugs- paracetamol, and aspirin in water. The proposed paper-based SERS substrate has been obtained by drop-casting of silver nanoparticles (AgNPs) over a 100 grams per square meter (GSM) paper. The performance of the designed SERS substrate has been initially evaluated with two Raman active samples - malachite green (MG) and rhodamine-6G (R6G). Upon noticing its reliable performance, the usability of the designed SERS substrate has been demonstrated to detect and quantify paracetamol and aspirin in the water medium. The applicability of the proposed SERS substrate in the real field environment has also been demonstrated through detection of these two drug elements in field collected water samples.