OBJECTIVES: Extensive floodwater damage following hurricane Harvey raised concerns of increase in invasive mould infections (IMIs), especially in immunocompromised patients. To more comprehensively characterize the IMI landscape pre- and post-Harvey, we used a modified, less restrictive clinical IMI (mcIMI) definition by incorporating therapeutic-intent antifungal drug prescriptions combined with an expanded list of host and clinical features. METHODS: We reviewed 103 patients at MD Anderson Cancer Center (Houston, Texas), who lived in Harvey-affected counties and had mould-positive cultures within 12 months pre-/post-Harvey (36 and 67 patients, respectively). Cases were classified as proven or probable IMI (EORTC/MSG criteria), mcIMI, or colonization/contamination. We also compared in-hospital mortality and 42- day survival outcomes of patients with mcIMI pre-/post-Harvey. RESULTS: The number of patients with mould- positive cultures from Harvey-affected counties almost doubled from 36 pre- Harvey to 67 post- Harvey (p < 0.01). In contrast, no significant changes in (mc)IMI incidence post-Harvey nor changes in the aetiological mould genera were noted. However, patients with mcIMIs from flood affected areas had significantly higher in-hospital mortality (p = 0.01). CONCLUSIONS: We observed increased colonization but no excess cases of (mc)IMIs in immunosuppressed cancer patients from affected areas following a large flooding event such as hurricane Harvey.