Samples of aligned MgB$_{2}$ crystallites have been prepared, allowing the identification of an upper critical field anisotropy $Hc2^{ab}/Hc2^{c}= xi_{ab}/xi_{c}~ 1.73; with xi_{o,ab}~ 70 A, xi_{o,c}~ 40 A, and a mass anisotropy ratio m_{ab}/m_{c}~ 0.3. A significant influence of Fe contamination was identified, possibly related to the purity of the raw materials.