Light elements can give us important information about the mixing processes inside stellar interiors. However, their depletion mechanisms are not completely understood yet. A wide spread in Li and Be abundances has been observed in clusters like M67 or NGC3960 as well as in field solar type stars but it cannot be explained with standard models.
In this talk I will present our last results about the possible relation between planets and Li depletion. We have found that in our sample of 300 solar analogues the planet hosts show Li average values lower than stars with no detected planets. Moreover, we find indications that the amount of depletion of Li in planet-host solar-type stars is higher when the planets are more massive than Jupiter. I will also talk about our sample of hotter stars (>5900K) where we find a group of stars with strong Li depletion but still far from the Li-dip. These stars indicate that non-standard processes like rotationally-induced mixing or episodic accretion may produce strong depletion of light elements.