The study explores factors influencing research and development (R&D) costs in developing economies. The findings may inform the decision-making process for firms keen on innovation-related expenditures. The paper examines 164 Kenyan firms using the World Bank Enterprise Survey (WBES) data for 2018. These factors are classified into three broad categories. These are firm characteristics (age, size, and ownership), business competitiveness (export orientation, innovation strategies, and informal competition), and technology upgrade challenges (skills availability, financial constraint, and technology incompatibility). The findings reveal that approximately 11% of firms incurring R&D costs export their products (services). Exportation, skilled labor availability, and degree of informal competition correlate positively and significantly to R&D expenditure. The largest ownership (%) has a marginal effect on the outcome variable. Moreover, firm size substantially influences R&D costs, with small to medium firms incurring lower costs than their larger counterparts. However, firm age, innovation strategy, financial constraint, and technology incompatibility weakly influence the outcome variable. The product innovation strategy’s interaction effect with skills, firm age and informal competition substantially impacts R&D costs. Notably, firms’ R&D spending must be in tandem with the domestic informal competition intensity, skills availability, and foreign market targeted. The study employs the Ordinary Least Squares (OLS) regression in examining the relationship between the predictors and the dependent variable.