The authors refer to the laboratory testing carried out on model caisson embedded in marine clay collected from the Chennai coast in India. The response of lateral loadground level deflection of caissons under static and cyclic lateral loading is presented and discussed for the varied parameters such as caisson embedment depth ratio (L= D), load eccentricity ratio (e=D), and undrained strength (s u ) of clay. The results showed that as the caisson L=D increases, the lateral load required to cause a specified ground level deflection increases. At a given lateral load, the deflection levels are increased as the load eccentricity ratio increases from 0.5 to 2.0. As L=D increases from 2 to 3, the increase in the ultimate lateral capacity is found to be 1.8 to 2.0 times. Similarly, for the change in L=D from 3 to 4, this increase in capacity is found to be 1.6 to 1.8 times at all the undrained strength values and e=D values tested. From the cyclic load test results, it was noticed that the deflections mobilized at the cyclic load ratio (CLR ¼ 0.6) were so small and these are hardly 1% to 2% of the diameter of the caisson. A marked increase in the ground level deflection up to about 900 cycles was observed and thereafter the deflection almost remained the same.Keywords cyclic load ratio (CLR), embedment depth ratio (L=D), ground level deflection, load eccentricity ratio (e=D), ultimate lateral load, undrained strength (s u )