Minimal information is available regarding the frequency with which practitioners conduct evaluations of capacity to waive Miranda rights or what approaches they use in doing so. Grisso's Instruments for Assessing Understanding and Appreciation of Miranda Rights are the only published instruments designed specifically to assist practitioners in these evaluations. The instruments have been criticized for limited normative data in the test manual and the minimal guidance offered for interpreting results. A survey of practitioners was conducted to determine the nature and frequency of the use of these instruments. Of 401 respondents, 91% were engaged in forensic practice, and 26% had conducted evaluations of one's capacity to waive Miranda rights. Of those conducting Miranda evaluations, 44% had used Grisso's Miranda instruments. Practitioners' responses regarding the ways the instruments are used are reported. Suggestions are offered for informed practice, and related strengths and weaknesses of the instruments are identified. (Contains 3 tables.)