Bleomycin instillation is frequently used to model lung fibrosis, although the onset and severity of pathology varies highly between mice. This makes non-invasive fibrosis detection and quantification essential to obtain a comprehensive analysis of the disease course and to validate novel therapies. Magnetic resonance imaging (MRI) of lung disease progression and therapy may provide such a sensitive in vivo readout of lung fibrosis, bypassing radiotoxicity concerns (when using micro-CT [μCT]) and elaborate invasive end point measurements (histology). We aimed to optimize and evaluate 3 different lung MRI contrast and acquisition methods to visualize disease onset and progression in the bleomycin-induced mouse model of lung fibrosis using a small-animal MRI scanner. For validation, we compared the MRI results with established μCT and histological measures of lung fibrosis.