To investigate the prevalence, risk factors and prognosis of invasive pulmonary aspergillosis (IPA) in patients with anti-melanoma differentiation-associated gene 5 positive dermatomyositis (anti-MDA5+ DM). A retrospective analysis was conducted in anti-MDA5+ DM patients diagnosed between January 2016 and March 2023. Patients with lower respiratory tract specimens were categorized into IPA+ and IPA- groups based on the presence of IPA and their clinical characteristics and prognoses then compared. Of the 415 patients diagnosed with anti-MDA5+ DM, 28 cases had IPA (prevalence rate of 6.7%) with Aspergillus fumigatus being the most common species. The patients were categorized into IPA+ (n=28) and IPA- (n=98) groups, with no significant age or gender-related differences (P>0.05). The IPA+ group had a lower lymphocyte count, particularly the CD4+ T-cell count, and reduced serum albumin and higher serum ferritin levels (P all<0.05). An elevated bronchoalveolar lavage fluid (BALF) galactomannan level was found to be the sole independent risk factor for the occurrence of IPA (adjusted OR=2.191, P=0.029) with a cut-off value of 0.585 and area under the curve of 0.779. The mortality rate in the IPA+ group was 25%. Compared to survivors, non-survivors in this group exhibited a higher incidence of rapidly progressive interstitial lung disease, lower lymphocyte counts, and increased co-infection with Pneumocystis jirovecii (P all<0.05). IPA was not rare in patients with anti-MDA5+ DM, with elevated BALF galactomannan levels being an independent risk factor for IPA occurrence. Clinicians must exercise vigilance to identify patients exhibiting the aforementioned risk factors.