Purpose: This paper aims to propose an integrated model based on buyer and supplier opportunism to show the mechanism through which current and competing suppliers influence buyer market competitiveness. Design/methodology/approach: Questionnaires were distributed to purchasing staff in listed electronics firms in Taiwan to collect empirical data. Structural equation modeling was used to analyze these data and examine the fitness of the proposed model. Findings: The findings show that current and competing suppliers influence buyer market competitiveness through supplier opportunistic behaviors and buyer commitment. The alternative attractiveness of competing suppliers affects buyer market competitiveness through the influence of asset specificity. Supplier opportunism negatively and indirectly influences buyer market competitiveness through buyer commitment. Nevertheless, buyer opportunism does not influence buyer commitment and market competitiveness. Research limitations/implications: The investigation focused on only one industry in one country. Future research could investigate other industries and countries to increase the generalizability of the findings. Practical implications: The results suggest that buyers can focus on utilizing the pressure of alternative suppliers to improve market competitiveness through increased specific investments by the current supplier. Originality/value: On the basis of buyer–supplier opportunism, this study shows the mechanism through which the asset specificity of current suppliers and alternative attractiveness influence buyer market competitiveness.