Abstract: Background and Objective: Sudden deaths from pneumonia is a common occurrence in many grasscutter farms in Ghana. Unfortunately, the cause of pneumonia remains unknown although some farmers believe it could be due to very cold environmental conditions especially during the rainy seasons. The objective of this study was to identify any microbial causation of sudden deaths due to pneumonia in grasscutters. Materials and Methods: Three adult grasscutters were presented for post-mortem examination with a history of sudden death. A thorough post-mortem was conducted and a morphological diagnosis was made based on gross post-mortem lesions. Lung and spleen samples were submitted for bacterial culture. Isolated bacteria were bio typed using the Bruker Matrix-Assisted Laser Desorption Ionization (MALDI) biotypes technique. Lungs, liver, spleen, trachea and adrenals were submitted for histopathological processing. Slides obtained were evaluated using light microscopy. Results: Post-mortem examination revealed gelatinous subcutaneous oedema at the ventral side of the neck, enlarged submandibular lymph nodes and pneumonia in all three carcasses. Microbiological evaluation of lung and spleen samples revealed Staphylococcus sciuri. Histopathological evaluation of lung sample showed diffuse expansion of alveolar and interlobular septae with the accumulation of eosinophilic proteinaceous precipitates admix with some dead and viable neutrophils and congestion. There was moderate to marked lymphoid depletion of white pulp in the spleen with poorly discernible colonies of coccoid bacteria. Conclusion: It was concluded that pneumonia in grasscutters resulting in sudden deaths could be due to infection of Staphylococcus sciuri and an associated shock syndrome due to septicaemia.