Systemic sclerosis associated interstitial lung disease (SSc-ILD) is an important source of morbidity and mortality in systemic sclerosis (SSc). Pulmonary function tests (PFTs) are a cornerstone for the diagnosis and follow-up of SSc-ILD, and are important for treatment decision. Aim: To analyze different patterns of evolution of PFTs in SSc. Method: We studied all consecutive SSc patients who performed PFTs in the last year in our department, focusing on those who had prior PFT values available for comparison.  We used the ATS/ERS/JRS/ALAT clinical practice guideline PFT cutoffs to define physiological evidence of progressive pulmonary fibrosis (Raghu et al., 2022). Results: Out of 44 SSc patients examined, 24 had previous PFT values (21 females, mean age 59). The follow-up period varied between 3 and 141 months. 13 (56.5%) patients had 5% FVC degradation between any two points during the entire follow-up period, only 7 of them worsening between the last two visits. The mean period between PFT exams showing decline was 28 months. Only 7 of the 13 had restrictive pattern impairment at the time of decline, the other 6 remaining in normal range. DLCO decline was seen in 7 out of 24 patients during a mean period of 39.1 months, only one of them with the lower value in the normal range. Out of the 6 patients that had significant decline in both DLCO and FVC, simultaneous changes were registered only in 4; in 2 of them the FVC degradation preceded the one of DLCO. All patients with functional decline had imagistic proof of interstitial fibrosis. Conclusion:  Close follow-up of SSc-ILD with PFT is important since functional evidence of progression may occur with PFT values still in the normal range.