In a proceeding pursuant to CPLR article 78 to review a determination of the Commissioner of the State of New York Division of Housing and Community Renewal, dated April 29, 1986, finding the peti*705tioner guilty of violating the Rent Stabilization Law and imposing penalties, the petitioner appeals from a judgment of the Supreme Court, Kings County (Lodato, J.), dated October 20, 1988, which dismissed the proceeding.
Ordered that the judgment is affirmed, with costs.
Substantial evidence may be defined as " 'such relevant proof as a reasonable mind may accept as adequate to support a conclusion or ultimate fact’ ” (People ex rel. Vega v Smith, 66 NY2d 130, 139, quoting 300 Gramatan Ave. Assocs. v State Div. of Human Rights, 45 NY2d 176, 180). In this case, the testimony of the DeCanios’, the tenants who brought the violations in question to the attention of the Commissioner, if true, established all of the facts necessary to sustain the charges against the petitioner Ausch. The Administrative Law Judge, after a hearing and consideration of many factors, including the DeCanios’ demeanor and possible self-interest, credited their testimony and rejected Ausch’s contentions. Those credibility determinations are supported by substantial evidence (Matter of Berenhaus v Ward, 70 NY2d 436, 444).
We have examined the petitioner’s remaining contentions and find them to be without merit. Bracken, J. P., Harwood, Miller and Ritter, JJ., concur.