This research investigates the losses resulting from the sudden contraction and expansion of a pipe culvert. A four hundred runs were carried out considering various angles and contraction ratios at inlet and outlet of the pipe culvert and downstream submerged ratios with different flow conditions. Results were analyzed and graphically presented. The results indicated that the inlet angle of 15ᵒ with width contraction ratio of (bu/D = 2.33) gives the least values of losses at the transition from a free-surface channel to the pipe culvert. For the transition from a conduit to a free-surface channel, the outlet angle of 60ᵒ with a submerged ratio of (hd/D = 0.20) and the outlet angle of 30ᵒ with submerged ratios of (hd/D=0.4, 0.6 and 0.8) give the least values of losses at width contraction ratio of (bd/D = 2.33).These results agree well with the results obtained from previous studies.