Scandium (Sc) is a promising candidate for theranostic applications due to the existence of radioisotopes suitable for both imaging and therapy. A “proof-of-concept” study regarding first-in-human use of ⁴⁴Sc for imaging metastatic neuroendocrine tumors was reported recently, however, quantitative assessment of ⁴⁴Sc-based PET images was not performed. The aim of this study was to evaluate quantitative capabilities of ⁴⁴Sc-PET using a commercial PET scanner. The NEMA/IEC body phantom with ⁴⁴Sc was acquired according to the local protocol used for whole-body oncological [¹⁸F]FDG PET examinations. Additionally, we characterized the signal recovery (recovery coefficient - RC) according to the iteration number. For all reconstructions, pertinent image corrections (normalization, dead time, activity decay, random coincidence, and attenuation) were applied. Presently, ⁴⁴Sc scatter corrections are not optimized and could, thus, result in quantitative bias. To investigate the best option, the data were reconstructed using different available scatter corrections (relative -RelSC- and absolute -AbsSC-) and an additional prompt-gamma correction (PGC). System cross-calibration with the local dose calibrator (BG_cal) and image noise, expressed by the coefficient of variation (COV), were evaluated in the homogeneous background region (5 kBq/mL) of the phantom. Maximum (RC_max) and 50% threshold recovery coefficients, corrected for background (RC_A50), were measured for all spherical inserts (25 kBq/mL) of the phantom. Acceptable COV (<15%) was achievable with low iteration numbers (<3). BG_cal differences were low: mean BG_cal were 77.8, 81.3, and 86.7%, for RelSC, AbsSC, and PGC, respectively. RC values exceeded the present RC range recommended for [¹⁸F]FDG procedures. Using the iterations to be evaluated, RC_A50 ranged from 29.9 to 59.9% for the smallest lesion (spherical insert of 10 mm diameter) and from 45.5 to 80.3% (13 mm), 66.4 to 75.6% (17 mm), 71.7 to 75.7% (22 mm), 75.1 to 78.6% (28 mm), and 76.7 to 80.9% (37 mm) for the, respectively spherical inserts. The results of this study show that clinical ⁴⁴Sc-PET imaging has the potential to provide signal recovery in lesions of different sizes comparable to current ¹⁸F-PET standards. In order to improve the quantitative accuracy of ⁴⁴Sc PET, optimized corrections are still necessary and will be investigated further in future.