In Japan, 4.6 million people are living with dementia and the number is expected to rise to 7 million by 2025. Amyloid-β (Aβ) positron emission tomography (PET) is used for cognitively normal Japanese people with or without subjective cognitive decline (SCD) for the purpose of clinical trials or diagnosis. Nevertheless, no empirical studies have been conducted on the safety of disclosing amyloid status to such populations. We conducted amyloid PET imaging on 42 participants (Aβ positive (n = 10) and negative (n = 32)). State anxiety and depression were measured at pre- and post-disclosure, and test-related distress at post-disclosure. Mean state anxiety and depression scores were below the cut-off through pre- and post-disclosure in the Aβ positive and negative groups. State anxiety and depression did not change over time and were not different between groups. Mean test-related distress scores were within normal limits at post-disclosure in both groups. No significant difference was found between groups. Disclosing Aβ positive results did not cause greater mood disturbance than negative results in a short period of time. The short-term psychological safety of disclosing Aβ PET results to asymptomatic Japanese adults with SCD was indicated.