The problem of the present study is that no reasonable explanation of the inferring relationships of crocodile; fish, and environment variables in Lake Nasser. This research article aims to find out the mysterious interrelationship of Nile crocodile abundance and reduction fish production in Lake Nasser. Data needed to achieve a meaningful explanation of the interrelationship of Nile crocodiles with fish production in Lake Nasser consist of two sets; data on abundance of species at a series of sites, and data on environmental variables measured at the same sites. These two matrices of data were analysed using Principal Components Analysis (PCA) technique in order to identify patterns in data, and expressing the data in such a way as to highlight their similarities and differences. PCA technique is useful in data of high dimension such as records on Nile crocodiles and fish production of Lake Nasser, where patterns in data can be hard to find by means of graphical representation. The present study provides meaningful explanation of the relationships of crocodile, fish catch and environment variables in Lake Nasser. The findings of this research work will determine the real reasons for decreasing the fish catch in Lake Nasser. Eradication of the causes of decline in fish production will lead to increased revenue.