Significant progress has been made in the development of disease-modifying drugs for amyotrophic lateral sclerosis (ALS), with the introduction of tofersen, an antisense oligonucleotide drug for familial ALS, marking a turning point in the treatment. These drugs are most effective when administered early in the disease course, highlighting the need for improved diagnostic sensitivity. The 2020 Gold Coast Diagnostic Criteria allow ALS diagnosis in cases without upper motor neuron symptoms, potentially increasing early detection rates. However, careful differential diagnoses are necessary when applying these criteria to maintain diagnostic specificity. This review outlines the key points to consider when using the Gold Coast Criteria, balancing the need for an early diagnosis with caution to avoid overdiagnosis.