This paper discusses the ethical and practical issues involved in the development and implementation of a preschool screening battery. A screening program is described and the resulting data presented in an attempt to illustrate the investment in time, money, and energy required. The ethical questions that arise because of the lack of cross-validation studies are discussed. It is suggested that the effectiveness of screening batteries has not been compared with other approaches which might be more economical and equally effective. In particular, the use of parent questionnaires offers possibilities because they provide the practitioner with more information than the simple referral of a child who has been identified by an informed parent, nursery school director, or primary grade teacher. The ability to generalize from any research data to the specific population to be considered for screening is open to question and validation of any screening technique is still needed to ensure that the effectiveness reported in the normative studies applies to the population being studied. (Author/SB)