This research examines the adverse effects of inferior innovative extensions on the brand innovability and quality of own parent brands from the perspective of consumer innovativeness. The results reveal that inferior radical innovations weaken the perceptions of brand innovability and quality of high-innovativeness consumers less than the perceptions of brand innovability and quality of low-innovativeness consumers. Conversely, inferior incremental innovations weaken the perceptions of brand innovability and quality of low-innovativeness consumers less than the perceptions of brand innovability and quality of high-innovativeness consumers. In comparison, brand innovability is less susceptible than brand quality to inferior innovation information. The threats of inferior innovations are less detrimental than expectation if the adverse effects are assessed with brand innovability, instead of brand quality. The findings suggest that brand innovability is a more justifiable indicator than brand quality in evaluating the adverse effects of inferior innovations.