Background: In recent years, there has been a growth of research on men's experiences of becoming fathers, most of which relates to a typically developing child without intellectual disabilities. While some studies have specifically explored the experiences of becoming a father of a child with an intellectual disability, there are few studies from an Irish context. Aim: The aim of this study was to present Irish fathers' narratives within the context of leading up to the diagnosis and the actual diagnosis of a child's intellectual disability. Method: A qualitative narrative inquiry design was used with ten fathers aged 31-48 years through semi-structured interviews. Results: This study is part of a larger study focusing on becoming a father of a child with an intellectual disability in Ireland. The findings related to finding out "something was wrong" with the child are presented. Conclusion: Fathers are emotionally affected by the diagnosis of a child's intellectual disability. Therefore, healthcare professionals need to be cognisant of the emotional upheaval that such a diagnosis can have on fathers and be sensitive to their needs in supporting them through this process.