For the favorable occurrence of mutual phenomena of the Galilean satellites in 1991, a special effort has been made in order to observe as many as possible events. A campaign of observation has been coordinated among 56 sites worldwide. Several techniques were used for these observations. A few observations were also made visually by amateur astronomers. They are presented in this paper only for the qualitative information that they provide for comparison with the other lightcurves. The whole set of observations is composed of 374 lightcurves of 111 events.