This study was designed to verify the risk factors for developing upper extremities musculoskeletal disorders (UEMD) among workers engaged in customer service tasks performed by telephone at a private banking corporation in São Paulo, Brazil. The monthly incidence of UEMD in hands and/or wrists in this group was studied retrospectively from January 1993 to June 1995. The statistical analysis was done by using multiple linear regression with the monthly incidence of UEMD considered as dependent variable in models controlled for age, seniority, mean daily regular worktime and overtime per operator, time pressure at work, rest/work schedule, management status, personnel training on postural and muscle stretching, and ergonomic hazards. The variables associated with UEMD were the following: time pressure at work (coefficient = 0.049; p = 0.008) and rest/work schedule (coefficient = -0.047; p = 0.02). The results indicate that working conditions are significantly associated with UEMD, and changes in the working schedule may decrease the incidence of this problem in workers assigned to tasks related to the interactive use of computer-accessible databases during telephone contacts.