Appeal from an order of disposition of the Family Court, Kings[*813] County (Schwartz, J.), dated August 16, 1982, which, upon a fact-finding determination, made after a hearing in the Family Court, Westchester County (Facelle, J.), that appellant had committed acts which, if done by an adult, would have constituted the crimes of assault in the second degree and assault in the third degree, adjudged appellant to be a juvenile delinquent, and ordered him placed in the custody of the New York State Division for Youth. Order reversed, and fact-finding determination vacated, without costs or disbursements, and matter remitted to the Family Court, Westchester County, for appointment of a guardian ad litem and a new fact-finding hearing, in accordance herewith. It was error for the court to accept appellant’s admission of the allegations against him without first requiring a “reasonable and substantial effort” to notify his parents, and then appointing a guardian ad litem, if such effort proved unavailing (Family Ct Act, § 741, subds [a], [c]). The obviously antagonistic position taken by the school in whose custody appellant was then placed renders the presence of its officials an inadequate substitute. Accordingly, appellant is entitled to a new hearing at which he will have the guidance of the appointed guardian (see Matter ofMyacutta A., 75 AD2d 774). Titone, J. P., Lazer, Mangano and Thompson, JJ., concur.