The capillary bed of the human renal glomerulus is one of the more complex capillary structures in the human body. This paper illustrates three-dimensional reconstruction of the capillary bed from serial sections. It shows that, although traditional methods of three-dimensional rendering by computer fail to handle the complexities of the capillary structure, new methods based on filtering using three-dimensional mathematical morphology are capable of revealing previously unseen details. This is done at the expense of eliminating fine structure (small capillaries). An error analysis allows the degree to which fine details are lost to be estimated.