This brief review of research examines the mail questionnaire as a research tool. Major topics reported are the advantages and disadvantages of mail surveys response rates, and questionnaire construction. Among the advantages reported are ease of distribution and tabulation, the possibility of a large sample and geographic range, low cost, uniformity of questions, convenience of response, and reduction of bias. Among the disadvantages are impersonal feelings, possible low rate of response, inability to interact with respondents, and lack of assurance as to the actual respondent. Strategies for increasing response rate are identified. Personalized correspondence, pre-contact letters, special delivery mailing, and emphasis on benefit to the respondent tend to increase response rates. Design of the questionnaire, clarity of instructions, simplicity of response, and quality of cover letter are considered to be important. A pilot test of the questionnaire to detect possible problems is recommended. (MDE)