Comprehensive investigations of the observed cluster radioactivity are carried out. First, the relativistic mean field (RMF) theory is employed for the calculations of the ground-state properties of relevant nuclei. The calculations reproduce the experiment well. The calculated RMF point densities are folded with the densitydependent M3Y nucleon-nucleon interaction to obtain the cluster-daughter interaction potential. This, along with the calculated and experimental Q values, is used in the WKB approximation for estimating the half-lives of the parent nuclei against cluster decay. The calculations qualitatively agree with the experiment. The discovery of the spontaneous emission of clusters heavier than α from very heavy nuclei is one of the most exciting findings in nuclear physics. The first successful experiment [1] on cluster radioactivity reported the observation of spontaneous emission of 14 C from 223 Ra. This observation substantiated the theoretical prediction of the cluster decays from heavier nuclei by Sandulescu et al. [2]. A number of experimental investigations since then have been reported (e.g., [3][4][5][6]), confirming the first experiment and adding some heavier decay modes. So far, about 30 such decays have been reported [7], and the search for other possible cluster decays is ongoing. However, such measurements are difficult to make because of the very small branching ratio of the cluster decay mode to the α decay mode of the parent nuclei [6,7].On the theoretical front, primarily two kinds of models have been advanced to describe the cluster decay modes: 1) the unified models, which treat the alpha decay, heavy cluster decay, and cold fission on similar footings, and 2) the cluster models. The analytic super asymmetric fission model (ASAFM) [8] and the effective liquid drop model (ELDM) [9] are examples of the former, whereas the 'square well' approach of Price et al.[4], the Buck-Merchant model [10], and the preformed cluster model [11] belong to the latter category. In addition, the R-matrix theory for the calculation of decay widths using the required input information obtained from the shell model/cluster model + BCS framework has been employed with reasonable success [12].Here, we present a comprehensive theoretical investigation of all the observed cluster (heavier than α) decay modes. First, we calculate the cluster-daughter interaction potential (nuclear) using the well-tested double-folding procedure [13,14]. This, along with the cluster-daughter Coulomb potential and the Q values, is used to obtain the decay half-lives in the WKB approximation.Explicit calculations are carried out in three steps. The ground-state properties are calculated first within the framework of the relativistic mean field (RMF) model [15][16][17]. * E-mail address: yogy@phy.iitb.ac.inThe required cluster-daughter potential is calculated next using the double-folding procedure [13,14]. Here, the densitydependent M3Y nucleon-nucleon interaction potential is folded with the calculated (RMF) daughter and cluste...