Crop losses in macadamia due to fruit diseases like husk rot caused by Diaporthe species and husk spot caused by Pseudocercospora macadamiae pose significant economic challenges for the industry. While data on kernel quality affecting prices after harvest provides some insight, it fails to capture the full extent of on-farm crop losses. This study investigates the impact of diseases that cause premature fruit drop in commercial macadamia orchards. Disease severity data, based on the amount of fruit drop from fruit set to mature kernel stage, were collected from seven orchards during the 2023–24 season. The results revealed that husk rot was the predominant fruit disease recorded across all regions at the early pre-harvest stage in December. Husk rot infections accounted for up to 40% of dropped immature fruits, equivalent to approximately 4,500 nuts in husk per hectare (NIH/ha). In the late fruit development stages in January, husk spot primarily affected the fruits, resulting in up to 30% of dropped immature fruits (~3,900 NIH/ha). The impact of these diseases varied significantly among regions. For instance, in January, husk spot prevalence was higher in Central Queensland (22%) and Northern New South Wales (28%) orchards than in South-East Queensland (15%) orchards. This difference may be attributed to variations in on-farm management practices and weather conditions. Additionally, cultivars showed differing susceptibility levels to these fruit diseases. For example, regional data indicates that cultivar 344 was more susceptible to husk rot across different regions than other commercial cultivars. These findings highlight the critical need for integrated disease management strategies to mitigate on-farm crop loss caused by two major fruit diseases, husk rot and husk spot, to ensure the sustainability and profitability of the macadamia industry.