A number of so far not correctly typified species of the genus Penicillium were re-examined. The profiles of secondary metabolites in old type strains and fresh isolates were compared. The type culture of P. implicatum Biourge was found to be identical with P. citrinum Thom. The first available name for P. implicatum sensu Raper & Thom is P. hispanicum Ramírez & al. Penicillium fellutanum Biourge and P. phaeojanthinellum Biourge are both considered to be synonyms of P. citrinum. Penicillium janthinellum Biourge sensu Raper & Thom agrees with the iconotype of Spicaria simplicissima Oud., while P. simplicissimum (Oud.) Raper & Thom sensu Pitt is conspecific with P. brasilianum Batista & al. Penicillium minioluteum Dierckx is redefined, based on an authentic type strain (Biourge 60 = CBS 642.68). Penicillium griseoroseum Dierckx is the first available name for P. chrysogenum Westling, but the latter name is to be protected by conservation. Penicillium olsonii Bain. & Sartory is considered to be a distinct species because it has a specific profile of secondary metabolites, clearly different from P. brevicompactum Dierckx. Penicillium solitum Westling is regarded as the correct name for dark (bluish) green strains previously called P. verrucosum Dierckx var. melanochlorum Samson & al. and P. mali Gorlenko & Novobranova.