About 50–60% of the average daily water consumption by humans is excreted as urine. It is high time to reconsider the aversion to such wastes and change the perception to view them as wealth instead of waste. In this line, in the current study, we have explored the possibility of using human urine as one of the feedstocks for biogas plants. In the current work, human urine is partially/fully replaced with water, and the potential for generating biogas and manure rich in nitrogen is studied. The purpose of using human urine in biogas system is two folds. (1) It is generally a waste disposed of through sewage lines, which initiates aerobic reactions in lines leading to a fouling smell and becomes pathogenic, and the maintenance of sewage lines is difficult and cost ineffective and (2) Human urine consists of nitrogen, phosphorous, and potassium in the following ratio as 11 parts, 1 part and 2.5 parts, which can improvise the biogas yield and manure quality as nitrogen present in the human urine work as the micronutrient for the feedstock degrading bacteria. Urine has a pH that varies from 4 to 8 and a high nitrogen content. It is a waste, and it is currently disposed of without any treatment in water bodies or barren lands. Various combinations of cow dung, food waste, urine, and water were mixed and studied in a lab-scale batch-type reactor. Ten such combinations with three samples for each combination were taken to check the repeatability and reproducibility of the results. The biogas yield is accessed for a retention period of 35 days and the yield is measured using the gas displacement method. Out of the ten combinations, a mixing ratio of 1:1:3 (rice waste, cow dung, and human urine) is found to be optimal with respect to maximum gas yield (230 l/kg) and manure fertiliser (Nitrogen, Phosphorus, and Potash) values. The optimum sample is again checked for gas yield, and the results are consistent with earlier experiments. The gas composition was measured, and it was found to be 62.10% methane and 37.90% carbon dioxide, which is in good agreement with the well-performing state-of-the-art biogas plants at present. Slurries derived from these studied samples, with optimal N-P-K values, can also be utilised for optimal growth and productivity in plants.