A case of acute intoxication presented as toxic pneumonitis after exposure to Roundup (glyphosate) (Solaris Group, Monsanto; San Ramon, CA) herbicide in an agriculture worker. The correct etiologic factor causing this specific clinical picture was identified only 2 weeks later, after a thorough occupational history was taken and meticulous delineation of the working conditions and exposures of the involved worker were made. As a rule, occupational related diseases are not readily elucidated by nonoccupational physicians. However, most acute intoxication events are first encountered by such physicians. In these situations, rapid and comprehensive evaluation is necessary in order to clearly identify the causative agent(s) and to initiate the appropriate treatment. Consulting occupational physicians at this early stage may facilitate early and accurate diagnosis.