This study sought to examine Perceived Stress, Perceived Social Support and Subjective Loneliness in Parents of Adolescents / Adults with Autistic Spectrum Disorder (ASD). Parents of children with ASD have reported elevated levels of stress. Effective social support can act as a buffer for parental stress. Studies have associated loneliness with depression and with poor mental and physical health. Effective social support may also have a role to play in mitigating loneliness. This study relied on a self-administered online questionnaire. Parents of adolescents / adults with ASD were contacted via the Parents Association of a south Dublin school for adolescents with ASD. There was shown to be a significant difference between Perceived Stress, Perceived Social Support and Subjective feelings of Loneliness of parents of adolescents / adults with ASD as against a Control Group. There was also shown to be correlation between perceived stress and subjective feelings of loneliness.