This cross-sectional and multicenter study aims to estimate the prevalence of upper limb musculoskeletal disorders (ULMSDs) and exposure to risk factors in industrial companies, through occupational physicians organized in an epidemiological sentinel surveillance network. Methods. In 2008, clinical data were collected using a questionnaire of the "Nordic" type for morbidity symptoms and clinical examination, according to the standardized diagnostic approach of the European consensus SAUSA. ULMSDs were classified into three degrees of severity after validation of the diagnosis via a decision tree. Data on risk :factors for ULMSDs were collected by a questionnaire including the biomechanical, psychosocial and Olganizational factors. Exposure scores were calculated for each anatomical area of the upper limb by addition of the risk factors revealed by the consensus. Results. Thus, 933 employees in eight industrial companies were included at random. Almost one in two workers in the past 12 months and one in four in the past seven days have suffered from non-specific upper limb musculoskeletal symptoms. The prevalence of diagnosed ULMSDs was high: 12% of the workers have sustained at least one proven form of unilateral or bilateral ULMSD, 6.3% a rotator cuff syndrome, 1.8% had lateral epicondylitis, 2.8% a carpal tunnel syndrome. The prevalence of ULMSDs increased with age and varied widely across companies and occupations. One in two workers was exposed to at least two risk factors for the upper limb, warning threshold of the SALTSA consensus. Conclusion. The use of the SALTSA protocol for the first time in Algerian companies revealed the importance of the prevalence of ULMSDs and of exposure to risk factors. These results show the need to structure the occupational physicians into an epidemiological sentinel surveillance network so as to develop a prevention program in most sectors and reduce the prevalence of ULMSDs. (C) 2010 Elsevier Masson SAS. All rights reserved.