Isovaleric acidemia (IVA) is characterized by periodic vomiting, lethargy, coma, ketoacidosis and a 'sweaty feet' odor. Hyperglycemia, ketonemia, ketonuria and metabolic acidosis are the main clinical features of diabetic ketoacidosis (DKA) and these same symptoms can also be seen in acute attacks of metabolic diseases. We report a 2-year-old patient who presented with acute encephalopathy, hyperglycemia, metabolic acidosis, increased anion gap, ketosis and a preliminary diagnosis of DKA. Further investigation revealed IVA. This case is of interest because of the rarity of this presentation and detection of a splicing mutation in the isovaleryl-CoA dehydrogenase gene.