Both the phase diagram and the phase-transition dynamics are studied for a simple model of phospholipid monolayers and bilayers. The phase diagram is studied using finite size scaling and phenomenological renormalization. The model predicts a first-order phase transition with a critical point. The phase-transition dynamics is investigated by the Monte Carlo method with Glauber dynamics. After quenching the system below the critical temperature, the average size of the growing domains l(t) is found to follow a t1/2 law.