This study aimed to evaluate both the feasibility of using ambient temperatures (15, 20 and 25°C) in a selfagitated anaerobic baffled reactor (SaABR) fed with swine wastewater, and the impact of decreasing the hydraulic retention time (HRT) down to 3 days. The highest specific methane yield (0.61 ± 0.14L/gVSin) and organicsconversationefficiency(66%onTCODbasis)wereattainedbyelevatingtemperaturefrom15to25°C under an HRT of 10 days. Even though the highest volumetric methane yield (0.85 ± 0.17L/L/day) was registered during a 3-day HRT, the specific methane yield was lower as a result of volatile fatty acids accumulations(upto790 ± 39mg/L).ThedominantbacteriumwasClostridiumsensustrictowhileMethanosaetawas thedominantarchaeathroughoutalltheconditions,indicatingstrongacetoclasticmethanogenicactivityunder ambienttemperatures.TheseresultsdemonstratethatusingambienttemperaturesandshortHRTsisapromising strategy to successfully treat wastewater with decreasing energetics entries. This can, thereby, increase the treatmentcapacityandenhancethemethaneyieldduringtheanaerobicdigestionprocess.