We tested endogenous pain modulation mechanisms in adults with autism spectrum disorders (ASD). Nineteen ASD adults without intellectual disabilities were included, matched with 19 healthy volunteers on the basis of sex and chronological age. An experimental pain model was used to measure excitatory and inhibitory pain mechanisms in a single session. Statistical analyses indicated that endogenous pain modulation mechanisms in ASD group did not differ significantly from those of healthy adults. The pain scores were very disparate in ASD group with a greater range of extreme scores than in control group. Unlike schizophrenic patients, there was no systematic dysfunction of endogenous excitatory pain modulation mechanisms, but the high variability requires to be wise to interpret the results and formulate conclusion.