Some physico-chemical parameters like temperature, pH, dissolved oxygen, ammonia-nitrogen, nitrite-nitrogen, nitrate-nitrogen, phosphate-phosphorus and silicate-silicon were investigated at the Mulki estuary under high and low tide conditions during monsoon, post and premonsoon periods. pH and salinity increased during high tides while dissolved oxygen trend is independent of tidal effects. Whereas ammonia, nitrite, nitrate, phosphate and silicate increased during low tide. Higher values of all the nutrients during monsoon season suggest that the freshwater influx can be a vital source of nutrients for the estuary.