Chi Sigma Iota (CSI) Counseling Academic and Professional Honor Society International is the international honor society of professional counseling and for professional counselors. CSI's mission is to promote scholarship, research, professionalism, leadership and excellence in counseling, and to recognize high attainment in the pursuit of academic and clinical excellence in the profession of counseling.

More than 176,000 counselors have been initiated into membership. This makes CSI one of the largest single member organizations of professional counselors in the world. More than 460 chapters have been chartered, and new chapters are being developed in the U.S and other countries as counselor education programs commit to meeting national accreditation preparation standards.

A student applicant for membership must be recommended by Viterbo's Delta Lambda Chapter after completing at least one semester of full-time graduate coursework in a CACREP-accredited counselor education degree program and having earned a grade point average of 3.5 or better on a 4.0 system. Students who meet these requirements will be invited by the Delta Lambda Chapter to a CSI initiation ceremony in the late Spring each academic year.