This study empirically analyzed the relationship between firms with high aggressive tax reporting tendencies and accruals quality, one of the attributes that determine financial reporting quality. In particular, this study examined whether, if a systematic positive (+) relationship exists between high tax reporting aggressiveness and low accruals quality, this relationship is more closely associated with innate accruals quality (InnateAQ) or discretionary accruals quality (DiscAQ)—the components of total accruals quality (TotalAQ) proposed by Francis, LaFond, Olsson, and Schipper (2005). Furthermore, additional analyses investigated whether these relationships differ according to chaebol affiliation or before and after the adoption of the new accounting standard, IFRS. For the analysis, this study targeted listed companies with December fiscal year-ends, excluding the financial industry, and used the five-year cumulative effective tax rates, GAAP ETR and CASH ETR, following the methodology of Dyreng, Hanlon, and Maydew (2008). Additionally, to establish the intervals for firms with high tax reporting aggressiveness, each ETR measure was divided into quintiles following the methodology of Donohoe and Knechel (2014), and firms in the lowest quintile were defined as having high aggressive tax reporting tendencies, after which the relationship with accruals quality was examined. The analysis period spans eight years from 2007 to 2014, covering four years before and after IFRS adoption. The empirical results of this study are as follows. First, even after controlling for certain variables that affect accruals quality, firms in the interval with high tax reporting aggressiveness exhibited significantly lower total accruals quality and innate accruals quality compared to those that were not. However, no significant relationship was observed for discretionary accruals quality, which incorporates managers' opportunistic motives. These results indicate that more aggressive tax reporting firms have lower financial reporting quality, higher information risk, and greater uncertainty in predicting future cash flows, and particularly suggest that high tax reporting aggressiveness is primarily associated with innate accruals quality. These findings were consistent whether analyzed using indicator variables or continuous ETR measures. Overall, the preceding results suggest that firms with higher tax reporting aggressiveness are associated with less transparent information environments. Second, as an additional analysis, when the sample was divided according to chaebol group affiliation, the first set of results was found to be primarily attributable to the non-chaebol group sample. In contrast, for chaebol group firms, those with high tax reporting aggressiveness exhibited higher total accruals quality and discretionary accruals quality. This suggests that the relationship between tax reporting aggressiveness and accruals quality shows differential responses depending on chaebol affiliation. Additionally, when the sample was divided according to the periods before and after mandatory IFRS adoption, the preceding results were primarily attributable to the period before mandatory IFRS adoption. That is, the positive (+) relationship between tax reporting aggressiveness and low accruals quality was found to be weaker in the post-IFRS period than in the pre-IFRS period. This appears to be due to changes in the information environment following the adoption of the new accounting standards, which weakened the positive (+) relationship between tax reporting aggressiveness and low accruals quality. In summary, the results of this study are significant in demonstrating, using a sample of domestically listed Korean firms, that firms with high tax reporting aggressiveness face higher information risk in terms of total accruals quality and innate accruals quality. Additionally, the results show that the positive (+) relationship between tax reporting aggressiveness and low accruals quality exhibits differential responses depending on chaebol affiliation and the periods before and after mandatory IFRS adoption, which is expected to provide additional empirical evidence for related research. In particular, since no prior domestic studies have examined the relationship between tax reporting aggressiveness or tax avoidance tendencies and financial reporting quality from the perspective of accruals quality, the findings of this study are expected to provide useful implications not only for academia but also for investors, practitioners, and regulatory agencies that supervise capital markets.