[Background] Presenteeism, defined as the practice of sick workers who come to work, and whose work performance effectiveness has been reduced due to various signs and symptoms, causes a significant financial loss to companies. However, comprehensive and effective occupational health countermeasures have not yet been presented. Therefore, we report here the results of an interim analysis to determine whether an allowance for acupuncture treatment is beneficial for workers' presenteeism. [Methods] A four-week randomized intergroup comparative study was conducted on office workers who were aware of their presenteeism. Participants were allocated to either the control group, in which regular recommended presenteeism countermeasures for each workplace were implemented arbitrarily, or to the intervention group in which an allowance of up to 8,000 was given for acupuncture treatment, in addition to the usual arbitrary measures. The primary endpoint was the WHO-HPQ relative presenteeism score: a score lower than 1 indicates lower work performance; and it was analyzed with the "full analysis set" population.[Results] A total of 52 patients were assigned to the intervention group (n = 30) and the control group (n = 22). On average, the intervention group received acupuncture treatments 1.4 times for stiff neck and shoulders (67%), lower back pain (26%), depression (5%), and allergies (2%), and paid a total of 7,219; and 6,556 was paid as an expense allowance. As a result, the relative presenteeism score was 0.95 in the intervention group, compared to 0.91 in the control group, with a between-group difference of 0.04 (ES (r) = 0.22, P = 0.12).[Conclusions] With a total of up to 8,000 offered to office workers who were aware of their presenteeism, an acupuncture treatment allowance for a four-week period was provided 1.4 times on average. The results suggested that the treatment allowance would increase workers' performance efficiency by about 4% (equivalent to 19,691 per person) compared to those without it.