Chilldown of cryogenic feed lines is the most indispensable part of any process that handles cryogenic fluids. Prediction of chilldown time ‘apriori’, requires a complete understanding of the influencing factors and the phenomenon involved. In the present study, the effect of feed line orientation and mass flux on chilldown performance is experimentally evaluated using liquid nitrogen. Experiments are carried out with a foam insulated stainless steel test section. Tests are performed for two different mass flux conditions with test section held in horizontal position as well as varying upward and downward inclinations. In tests with upward orientation, a significant jump in heat flux at top region is seen when the wall superheat reduces below a critical value and this is attributed to onset of liquid wetting at top region. In tests with downward inclination, a minor increase in the heat flux at top region is seen beyond 30° downward orientation attributable to the flow structure prevailing in the test section. It is noted that heat flux pattern at bottom region is not influenced much by test section orientation. Leidenfrost temperature, minimum wall heat flux, and critical heat flux values obtained from the present study are compared with the predictions made using correlations available in published literature. The findings of the present study would help to understand better the influence of feed line orientation and mass flux on wall heat flux pattern and thereby improve the prediction capability.