Anaerobic digestion can use cow manure and waste paper to produce energy in the form of flammable biogas. The grouping of these substrates is not well studied in comparison to other waste feedstocks. Finding ideal operating parameters and models to predict biogas production are vital for future studies and applications. Office paper and cow manure were combined in different ratios at 38.5°C. Four models (Time-Lag, No-Lag, Modified Gompertz, Modified Logistic) were fit to the experimental data to determine which model best predicted biogas production. The digester containing a paper to manure ratio of 2:1 generated the most biogas, but the 5:1 reactor had the greatest biogas production potential based on the model predictions. Models were not consistent in the accuracy of their fit to the data for each treatment. The use of various models when examining anaerobic digestion is important to ensure the best models are selected for future studies.