A witness may not testify to a matter unless evidence is introduced sufficient to support a finding that the witness has personal knowledge of the matter. Evidence to prove personal knowledge may consist of the witness's own testimony. This rule is subject to the provisions of Section 2703 of this title.
§ 2602.Personal Knowledge
Chapter 40: Oklahoma Evidence Code · Last amended November 1, 2002 · Last verified August 3, 2026
In one sentenceSection 2602 bars a witness from testifying to a matter without evidence sufficient to support a finding of personal knowledge, though the witness's own testimony can supply that foundation, subject to the expert-opinion rule in Section 2703.
Full Text of § 2602
Amendment History
Laws 1978, SB 276, c. 285, § 602, eff. 10/1/1978; Amended by Laws 2002, HB 1939, c. 468, §42, eff. 11/1/2002.
Plain-English Summary
Before a witness can testify to something, there has to be a foundation showing the witness knows it firsthand. Section 2602 requires evidence sufficient to support a finding of personal knowledge, and the witness's own testimony can serve as that evidence. The rule expressly gives way to Section 2703, which governs expert opinion testimony and doesn't require the same firsthand-knowledge foundation.
Frequently Asked Questions
How does a witness establish personal knowledge of a fact?
Section 2602 allows the witness's own testimony to serve as the evidence supporting a finding of personal knowledge.
Does this rule apply to expert witnesses?
Section 2602 is expressly subject to Section 2703, the Code's rule on expert opinion testimony.
What happens if there's no evidence a witness has personal knowledge of a matter?
The witness may not testify to that matter.
Source & verification. Section text is reproduced verbatim from
Title 12 of the Oklahoma Statutes, enacted by the Oklahoma Legislature.
Last verified August 3, 2026.
· Official source
Also known as: personal knowledge requirement witness oklahomaFRE 602 oklahomalay witness foundation oklahoma evidence12 O.S. § 2602