The biological species currently known within the Anopheles maculatus group in Thailand are formally recognized. Descriptions are given for the adult and egg stages of maculatus Theobald, willmori James, pseudowillmori Theobald, dravidicus Christophers, sawadwongporni n. sp. and notanandai n. sp. The descriptions are based on an extensive study of progeny broods from wild-caught females that were identified from chromosomal rearrangements observed in their ovarian polytene chromosomes. Lectotypes are designated for maculatus, willmori and dravidicus. A preliminary key is provided for the identification of adult females.