Developed by Scala (1959), the dynamic cone penetrometer (DCP) has been extensively used in recent decades for the design of flexible pavements due to its inexpensive and easy-to-operate features. This paper presents some of the results of a study concerning the effect of vertical confinement from the CBR mould on the dynamic cone penetrometer index, and the development of a lightweight DCP that can be used in the laboratory as well as in field conditions with similar results. The results show that the effect of vertical confinement is very significant, especially with a hammer mass larger than 4.6 kg. The results also indicate that the influence of the vertical confinement on the penetration index is not significant when the hammer mass is less than 2 kg. Based on these results, a new lightweight DCP is proposed with a hammer mass of 2.25 kg, which can be used in the laboratory in the CBR mould and also in field conditions with similar results for a similar soil.