The effect of adsorption and temperature (300-450 K) on the electrical resistivity of SnSe thin films on the thickness range 500-2500 AA was investigated. Adsorption of oxygen has considerable influence on the electrical resistivity and it is observed to act as a p-type dopant. The temperature variation of resistance indicates interesting irreversible behaviour in the first heating cycle and the behaviour is suspected to be due to acceptor formation at higher temperatures. Adsorption and annealing were found to have a significant effect on the temperature variation of the resistance of SnSe thin films.