Context : The X-shooter Spectral Library ( XSL ) is an empirical stellar library at medium spectral resolution covering the wavelength range from 3000 Å to 24 800 Å .
This library aims to provide a benchmark for stellar population studies .

Aims : In this work , we present a uniform set of stellar atmospheric parameters , effective temperatures , surface gravities , and iron abundances for 754 spectra of 616 XSL stars .

Methods : We used the full-spectrum fitting package ULySS with the empirical MILES library as reference to fit the ultraviolet-blue ( UVB ) and visible ( VIS ) spectra .
We tested the internal consistency and we compared our results with compilations from the literature .

Results : The stars cover a range of effective temperature 2900 < T _ { \mathrm { eff } } < 38 000 K , surface gravity 0 < \log g < 5.7 , and iron abundance -2.5 < [ Fe / H ] < +1.0 , with a couple of stars extending down to [ Fe / H ] = -3.9 .
The precisions of the measurements for the G- and K-type stars are 0.9 % , 0.14 , and 0.06 in T _ { \mathrm { eff } } , \log g , and [ Fe / H ] , respectively .
For the cool giants with \log g < 1 , the precisions are 2.1 % , 0.21 , and 0.22 , and for the other cool stars these values are 1 % , 0.14 , and 0.10 .
For the hotter stars ( T _ { \mathrm { eff } } > 6500 K ) , these values are 2.6 % , 0.20 , and 0.10 for the three parameters .

Conclusions :