EXHIBIT 23 CONSENT OF INDEPENDENT ACCOUNTANTS We hereby consent to the incorporation by reference in the Registration Statement on Form S-8 (No. 333-91671) of National Instruments Corporation of our report dated January 21, 2004 relating to the consolidated financial statements and the financial statement schedule, which appears in this Form 10-K. /S/ PRICEWATERHOUSECOOPERS LLP -------------------------------- PricewaterhouseCoopers LLP Austin, Texas January 26, 2004