Occupational health research depends on the cooperation and participation of employers. The authors describe employers' reasons for non-participation in a prospective study examining risk factors for carpal tunnel syndrome (CTS) and the usefulness of preplacement, post-offer nerve conduction screening. Companies were contacted to solicit participation. Non-participation explanations were reviewed. Of 73 eligible employers, 58 declined participation (participation rate: 20.5%). Reasons for non-participation included lack of interest (32.8%), liability concerns (awareness of CTS may increase workers' compensation claims) (22.4%), time constraints (19%), lack of direct benefit to the employer (8.6%), and company policy restraints (6.9%). Data from one employer were reviewed to determine whether workers' compensation claims for upper extremity disorders increased as a result of study participation. Claim rates showed no change in trend pre- and post-study inception. Expanding much-needed research to prevent occupational injuries and illnesses requires addressing employers' concerns and promoting research benefits.