This study examined the association between cooperative work climate and business owners' attitudes toward work climate and help-seeking intentions for balancing medical treatment and job (BTJ) by occupation among employees of small companies. In January 2024, we conducted an online survey of 1,800 full-time employees aged 20-64 years with no work restrictions due to illness working in small companies. After participants were provided a leaflet regarding BTJ, they were asked to indicate their intention to seek help in an imaginary situation where they had been diagnosed with cancer. We conducted a multivariate logistic regression analysis using a combination of cooperative work climate (low or high) and business owners' attitudes toward work climate (low or high) as the primary explanatory variable and help-seeking intentions regarding BTJ as the dependent variable, adjusted for relevant job-related variables. As a subgroup analysis, logistic regression analyses by occupation (i.e., white- or blue-collar workers) were also conducted. Among the 1,800 participants (602 females and 1,198 males), 1,350 (75.0%) reported an active intention to seek help regarding BTJ. Those who reported higher levels of cooperative work climate and lower levels of business owners' positive attitudes toward work climate (odds ratio (OR) 1.5, 95% confidence interval (CI) 1.07-2.1), as well as those who reported higher levels of work climate and business owners' attitudes (OR 2.0, 95% CI 1.4-2.9), were significantly more likely to reveal help-seeking intentions regarding BTJ than those who reported lower levels of work climate and business owner attitudes. Analyses by occupation also showed that for both occupation categories, those who reported higher levels of cooperative work climate and business owner attitudes toward work climate more frequently revealed help-seeking intentions than those who reported lower levels of work climate and business owner attitudes. Among participants working for small companies, regardless of occupation, those who reported higher levels of cooperative work climate and business owners' attitudes toward work climate were significantly more likely to reveal help-seeking intentions regarding BTJ. Our findings imply that (1) cooperative work climate has a stronger effect on help-seeking intentions regarding BTJ than business owners' attitudes toward work climate, and (2) both work climate and business owners' attitudes have a synergistic impact on help-seeking intentions regarding BTJ. Enhancing a cooperative work climate may promote help-seeking intentions among employees working for small companies, regardless of occupation.