Introduction: Pregnancy is a specific condition that modifies the mobility of women. In this population, it seems important to use specific tools to properly assess them. The Pregnancy Mobility Index (PMI) was created in 2006 with the aim of assessing mobility in pregnant women. The goal of this study was to translate, adapt, and evaluate the statistical properties of the questionnaire in the Italian pregnant population. Methods: The PMI underwent translation and transcultural adaptation. Reliability and concurrent validity, compared to the Oswestry Disability Index (ODI), was investigated on a sample of pregnant women. An ANOVA was performed to detect differences in the PMI score considering the Body Mass Index (BMI) and age of the sample. Results: The PMI was forward translated, back translated, and transculturally adapted. A consensus meeting accepted the final version of the questionnaire. The PMI was given to 93 pregnant women. PMI showed excellent reliability for every item and the total score (Cronbach’s alpha of 0.945). Concurrent validity compared with ODI items 2–9 was strong considering the total score, with r = 0.726, but moderate comparing the first item of the ODI and the total score of the PMI, r = 470, and considering the total score of both questionnaires (r = 0.683). The ANOVA showed statistical difference in pregnant women with lower BMI for every subscale and total score of PMI (p = 0.009) and for outdoor mobility considering age (p = 0.019). Conclusions: The PMI seems to be a valid and reliable tool to assess mobility in the pregnant population. Pregnant women with a lower BMI showed a greater mobility score in the PMI. In turn, younger pregnant women presented a lower mobility score compared to older pregnant women.