This study investigates the effect of product cost management on the profitability of consumer goods firms in Nigeria, focusing on material cost control and labour cost management as key dimensions of cost management. Profitability was measured using gross profit margin and net profit margin. The study employed a descriptive and explanatory research design, utilizing secondary data extracted from the audited financial statements of ten consumer goods firms listed on the Nigerian Stock Exchange over a five-year period (2018–2022). Data were analysed using descriptive statistics and multiple linear regression to examine the relationship between product cost management and profitability. The findings reveal that both material cost control and labour cost management positively and significantly influence gross and net profit margins. Material cost control was found to have a stronger effect, highlighting the sensitivity of profitability to fluctuations in raw material costs. The study further showed that product cost management jointly explains 71.4% of the variation in gross profit margin and 62.3% of the variation in net profit margin, indicating that effective cost control practices are critical determinants of financial performance in Nigerian consumer goods firms. Based on the results, the study concludes that efficient product cost management enhances firm profitability and recommends that firms adopt integrated cost control systems, invest in workforce efficiency, and implement modern inventory and production management practices.