A method, system, computer program product, and computer program storage device for performing a memory leak analysis inside a virtual machine is disclosed. By utilizing thread stack(s), class statics, and/or a list of root objects, a DFS algorithm starts execution at root objects in the thread stack(s), class statics, and/or a list of root objects. Upon fully processing an object, a reachability (sum of sizes of all child objects plus a size of the object itself) of the object is calculated. When the reachability of the object is larger than a threshold and when all reachabilities of children of the objects are less than another threshold (i.e., a largest child reachability of the object is less than another threshold), the object is determined as a potential source of a memory leak.