In 1984, we initiated a prospective study of factors associated with research-defined carpal tunnel syndrome (CTS) in 471 industrial workers. Medical history, lifestyle factors and job tasks were assessed by questionnaire and CTS case status was based on both symptoms and electrophysiologic findings. Participants were re-examined in 1989, 1994 to 1995 and 2001 to 2002. This study reports both baseline and aggregated risk factors associated with increased risk of CTS by 2001 to 2002 for 166 participants successfully re-examined after 17 years. In analyses of baseline risk factors, fewer repetitive tasks at work, female gender and greater relative weight were associated with any occurrence of CTS during follow-up. In analyses of aggregate risk factor scores through 1994 to 1995, only greater relative weight and female gender were associated with CTS in 2001 to 2002. Although obesity and gender are consistent predictors of CTS, workplace demands appear to bear an uncertain relationship to CTS. These findings are also discussed in relation to the possible differences between research-defined CTS and medically referred CTS.