Studies were carried out to determine relationships between morphometric and dimorphic variables of freshwater crab, Potamon ebonyicum. Parameter measurements were taken from side to side (left and right); and from tip to the extremity of characteristic features, to ensure that values were obtained at the widest points. The dimorphic variables showed positive correlation and linear relationship between male and female. Nonlinear relationship was recorded in most variables morphologically.  Regression analyses revealed poor correlation between carapace length (CL) and weight, and between carapace width (CW) and weight. There was a positive correlation between CL and CW of both sexes. The findings could be a guide for determining condition factor.  They could also be useful in field identification and further classification of freshwater crab.