Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder with an unknown etiology and currently few effective therapies. Immune system alterations have being demonstrated in ASD, both in humans and via animal models; immune imbalance thus arises as a possible pathway for drug intervention. In this review, the studies were classified into 2 major groups: (1) clinical research whose authors classify therapies with primary anti-inflammatory and immunomodulatory actions, making use of: sulforaphane, celecoxib, lenalidomide, pentoxifylline, spironolactone, flavonoid luteolin, corticosteroids, oral immunoglobulin, intravenous immunoglobulin, cell therapy, dialyzable lymphocyte extracts, minocycline, and pioglitazone; and (2) other ASD therapies already used or currently under study whose initial characteristics were neither anti-inflammatory nor immunomodulatory initially, but displayed a capacity for immunomodulation throughout the treatment: risperidone, vitamin D, omega-3, Ginkgo biloba, L-carnosine, N-acetylcysteine, and microbiome restoration. These studies used various data acquisition methodologies. Questions arose such the need for randomized and placebo-controlled studies with greater numbers of participants as well as the use of biomarkers to refine the treatment of autistic subjects.