This study investigates thermophilic anaerobic Co-digestion of an alkali treated Musa sapientum plant waste (MSPW) and cattle dung for biogas production and its statistical analysis using a one factor response surface methodology (RSM). Proximate compositions of slurry and analysis of microbial count load were carried out with the aids to determine the potential use of spent slurry. Results show highest experimental biogas yield of 2.915 10-2m3/day on 19th day. Statistical analysis show the predicted biogas yield of 2.834 10-2m3/day on 19th day. Using this predicted day, the experiment was validated in triplicate and the average optimum biogas yield was 2.82 10-2m3/day. Analysis of variance (ANOVA) of regression equation shows that the coefficient of determination (R2) of was 63.81%.Temperature of the slurry measured during the fermentation was within mesophilic temperature (30-40 ). Proximate compositions of the substrate and digestate obtained in this study shows a decreasedin ammonia nitrogen, total phosphate, total alkalinity, potassium, dissolved oxygen (DO), iron/10 and total copper after the anaerobic digestion while the pH, aluminium, calcium, magnesium, zinc/35TT, total solid and carbon content increased after the anaerobic digestion process. Microbial load count results showed 6.3 x 10-2Cfu/ml digestate, 4.6 x 10-2Cfu/ml of substrate and 5.5 x 10-3Cfu/ml inoculum. Hence, it can be concluded that an alkali treated MSPW mixed with cattle dung at a 1:1 w/w ratio, showed an increase in biogas production and the spent slurry of this process can improve organic manure for agricultural production.