This study investigated the diagnostic capacity for Fetal Alcohol Spectrum Disorder (FASD) in multidisciplinary clinics across several provincial and one territorial jurisdictions of Canada: Alberta, British Columbia, Manitoba, Ontario and Northwest Territories. The data were collected directly from clinics capable of providing diagnoses of FASD and examined annual capacity for the assessment and diagnosis of FASD per year from 2015 to 2019. In total, 58 FASD diagnostic clinics were identified and 33 clinics participated in this survey. The study identified inadequate FASD diagnostic capacity in all participating jurisdictions. Based on the findings and the current population sizes, it is estimated that 98% of individuals with FASD are undiagnosed or misdiagnosed in Canada. Wait times for FASD diagnosis ranged from 1 month to 4.5 years across participating jurisdictions. The annual FASD diagnostic capacity in the select provinces and territories require at least a 67-fold increase per year.