In Morocco, the transformation of hides into leather uses many hazardous chemicals such as chromium and sulfide, which have many negative impacts on workers’ health and the environment as well. In this regard, this work has undertaken the evaluation of the occupational health hazards of tanneries′ workers in Fez-Morocco by analyzing different symptoms of dermatitis and Oto-Ryno-Laryngological disorders (ORL). This study was based on cross-sectional descriptive epidemiological surveys, which were conducted in many tanneries of Fez city. Moreover, it concerned 302 workers focusing on a medico-social questionnaire and statistical analyses. The statistical analysis results of the questionnaires showed the prevalence of many diseases, particularly dermatitis (skin lesions: 19.2%; eczema: 26.5%; fungal: 18.2%) and ORL symptoms (stuffy nose: 58.3%; rhinitis: 47.4%; headaches: 30.8%). As well, the results showed a strong correlation between the number of working years, the tanning sectors, the use of protective equipment and the appearance of these diseases, while the results of the self-reported character of the symptoms revealed that the units of unhairing liming and chrome tanning are the most toxic sectors due to many detected cases of ORL and dermatitis over there. Subsequently, these results indicate that tanners are daily exposed to hazardous risks because of the chemical products used. Thus, all responsible authorities must be involved to find urgent solutions to solve the tanners’ life.