Diogenes syndrome or senile squalor syndrome has been described in the psychiatric literature with an associated mental illness in between one half and two thirds of the cases cited. The occurrence of the syndrome in the absence of a psychiatric disorder has received much attention with many hypotheses proposed. We present the case of a 72-year-old man living for many years in domestic squalor whose presentation, neuropsychological profile and history suggest an underlying autistic spectrum disorder. We are not aware of any similar case in an older adult reported in the medical literature. The co-occurrence of these two conditions is an intriguing one as certain key features of autistic spectrum disorder may predispose to Diogenes syndrome.