A system comprising at least: a first container 22 containing at least a first surgical instrument of a first type 32 that is size specific and a second surgical instrument of a second type 34 that is size specific, wherein both the first and second instruments are of a first size; a second container 24 containing at least a third surgical instrument of the first type and a fourth surgical instrument of the second type, wherein both the third and fourth instruments are of a second size which is different from the first size; and a third container 30 containing at least a fifth surgical instrument of a third type which is size independent. The system allows instrumentation to be grouped and stored so that the number of instruments opened but not used in complex surgical procedures is reduced. The combination of the first and second containers (with instruments of a single size) allows the system to group instruments according to size and/or function, avoiding the need to open containers with instruments of a size that is not being used. The third container can provide instruments that may be used at more than one point in the procedure, to avoid needing to provide multiple instruments in different containers and to simplify inventory. The third container may also provide instruments used for determining the required size of the instruments in the first and second containers.