Dumbbell shaped aggregates are small particles synthesized in precipitation reactors. Their characterization by optical methods needs the chord length distribution (CLD) of such a shape. We present in this paper the analytical calculation of two CLDs corresponding to two different definitions of CLD. Comparison with Monte-Carlo simulations is presented. Good agreement is found between the exact calculation and simulations. (C) 2013 Elsevier B.V. All rights reserved.