In the course of recent field surveys, specimens of the lizardZonosaurus brygooiLang & Böhme 1990 were collected at two localities in northeastern Madagascar (Besariaka and Tsararano rainforests), which are situated about 50–70 km north of Nosy Mangabe, the northernmost population so far reliably known. The species was not found at Anjanaharibe and Marojejy massifs, nor in the corridor which connects these areas. One specimen collected at Andohahela in the South-East, about 750 km south of Betampona, the southernmost population so far known, is provisionally referred to Z.brygooi.It differs, however, by the presence of four supralabials anterior to the subocular, a character that may indicate its taxonomic distinctness. Together with two new locality records of Z.aeneus(Grandidier 1872), the new material enables us to discuss the distribution and zoogeography of the Z.aeneusgroup (Z.aeneus, Z. brygooi, Z. rufipesand Z.subunicolor), and to describe the genital morphology of Z.brygooifor the first time. Our data indicate a possible seasonal variation in the hemipenis ornamentation of the species.