A continuous numerical scale for assessing the severity of pulmonary fibrosis in lung tissue samples was developed to correlate with other pulmonary variables such as lung function tests or mineral burden. The scale ranges from 0 to 8, based on the average of microscope field scores. This system allows for the measurement of fibrosis in small tissue samples (1 cm), providing a detailed description of lung changes not possible with existing methods. The method involves scanning paraffin sections of lung tissue stained with haematoxylin and eosin or trichrome, using a ×10 objective. Each field is scored for fibrosis severity on a 0-8 scale, with the mean score of all fields representing the fibrosis score for the section. The predominant fibrosis level in each field is recorded, and fields with non-fibrotic elements are excluded. Intraobserver variability was assessed by having one observer score 20 slides of asbestos-exposed lung tissue five times. The results showed high repeatability, with a coefficient of variation under 10%. Interobserver variability was also assessed, revealing significant differences between observers, though observer 3 (TA) showed no significant difference between scores on two occasions. The method allows for fine gradation of fibrosis, providing a continuous numerical scale from 0 to 8 that can be correlated with other continuous measurements. It is applicable to biopsy specimens and can be used to map fibrosis extent and severity in necropsy lungs. However, caution is needed when extrapolating scores from small biopsy samples to whole lungs due to possible variation in fibrosis severity. The method is applicable to various fibrotic pulmonary conditions, not just asbestosis, as it recognizes common histological changes in individual fields. Previous schemes for assessing fibrosis were limited to broad categories, whereas this method provides a more detailed and continuous assessment. The method's reliability was confirmed through statistical analysis, showing high repeatability and reproducibility.A continuous numerical scale for assessing the severity of pulmonary fibrosis in lung tissue samples was developed to correlate with other pulmonary variables such as lung function tests or mineral burden. The scale ranges from 0 to 8, based on the average of microscope field scores. This system allows for the measurement of fibrosis in small tissue samples (1 cm), providing a detailed description of lung changes not possible with existing methods. The method involves scanning paraffin sections of lung tissue stained with haematoxylin and eosin or trichrome, using a ×10 objective. Each field is scored for fibrosis severity on a 0-8 scale, with the mean score of all fields representing the fibrosis score for the section. The predominant fibrosis level in each field is recorded, and fields with non-fibrotic elements are excluded. Intraobserver variability was assessed by having one observer score 20 slides of asbestos-exposed lung tissue five times. The results showed high repeatability, with a coefficient of variation under 10%. Interobserver variability was also assessed, revealing significant differences between observers, though observer 3 (TA) showed no significant difference between scores on two occasions. The method allows for fine gradation of fibrosis, providing a continuous numerical scale from 0 to 8 that can be correlated with other continuous measurements. It is applicable to biopsy specimens and can be used to map fibrosis extent and severity in necropsy lungs. However, caution is needed when extrapolating scores from small biopsy samples to whole lungs due to possible variation in fibrosis severity. The method is applicable to various fibrotic pulmonary conditions, not just asbestosis, as it recognizes common histological changes in individual fields. Previous schemes for assessing fibrosis were limited to broad categories, whereas this method provides a more detailed and continuous assessment. The method's reliability was confirmed through statistical analysis, showing high repeatability and reproducibility.