The Victoria Park surface failed a second inspection and referee Darren Bond had no other option but to call the game off.
A statement on the Hartlepool website read: "Today's game with Portsmouth has been postponed after referee Darren Bond carried out a second inspection of the Victoria Park pitch.
"Heavy rain throughout the week has left the playing surface extremely wet and more showers this morning caused concern for the match official.
"With forecasts suggesting further heavier rain is on the way later this morning and in to the afternoon - and with the knowledge of visiting fans making a long journey - the referee felt there was no alternative but to call the game off."
There is no new date for the game as yet.