In a rhombus, all sides have the same length. Therefore, if one side of a rhombus is 8cm, then all sides are 8cm.
The perimeter of a rhombus is the sum of the lengths of all four sides. Since all sides of this rhombus are 8cm, the perimeter is:
4 x 8cm = 32cm
Therefore, the perimeter of the rhombus is 32cm.