The Federal Statute and Pertinent Rules of Evidence were enacted to bring the realities of business and professional practice into the courtroom in usable form. The use of computers, electronic data, and processing and storage equipment has expanded to the extent that the laws must address their use, particularly with regard to the hearsay rules. Types of materials that may be involved in litigation include manufacturers' specifications for computers, logs of computer operations, and original documents in traditional form which provide basic information for computer input. Computer records will often require expert explanation to render them understandable to the layman. This may entail translation of code or symbols. Computer output for use as evidence is available, under delineated conditions as provided in the Federal Rules of Evidence, in civil and criminal proceedings and in administrative hearings. Records maintained in or by computers kept in the regular course of business are admissible under certain conditions. The record must have been made at or near the time of the event recorded. In a legal proceeding, a general objection to admission of computer evidence is insufficient. Factors in determining the weight of computer evidence include demonstrated accuracy, security of the data, and discovery procedures. Use of a pretrial checklist which addresses such issues as the type of computer used, type of records produced, program modifications, and methods used to correct errors is suggested for evaluation of computer evidence. The basic rule in both Federal and State courts is that the acceptability of computer evidence depends on the reliability of the machine and the efficiency of detailed programs to prevent errors and ensure trustworthiness. Sixty-four footnotes are included.