The relation between product-market competition and voluntary corporate disclosure is fundamental, but empirical evidence of this relation has been mixed. One reason for the mixed evidence could be that both competition and disclosure are multidimensional. In this study we introduce a firm-specific measure of the technological aspect of competition—technological peer pressure—to the accounting literature and examine an overlooked type of voluntary disclosure—firm-initiated product-development-related press releases (“product disclosure”). We argue that empirical examinations of the theorized negative relation between competition and disclosure require the type of voluntary disclosure to be relevant to the dimension of competition under examination to ensure that firms incur significant proprietary costs of disclosure. We expect a negative relation between technological peer pressure and product disclosure because the latter reveals firms’ strategies, allocations, and progress of technological investments in product development to competitors. In contrast, we do not expect a negative relation between technological peer pressure and management earnings forecasts—the most common type of voluntary disclosure used in accounting research—because earnings projections reveal little about technological investments. Our test results are consistent with these expectations. Our study highlights the importance of understanding the multidimensionality of product-market competition and voluntary disclosure.