Alexithymia is a personality construct characterized by a cognitive and an affective deficit in recognizing and communicating emotional states. The present research investigated the relations between alexithymia, well-being, and romantic relationships in 437 undergraduates. High levels of alexithymia were found in 18.5 % of the sample and were associated with high levels of depression and negative affect, and low levels of life satisfaction, happiness and positive affect. Alexithymia was also negatively correlated with the quality of romantic relationships and with commitment, romance, trust, satisfaction and love in romantic relationships. The relation between alexithymia and subjective well-being was mediated in part by the poor quality of their romantic relationships. Alexithymia accounted for significant portions of the variance in depression (19.0 %), negative affect (17.4 %), life satisfaction (14.4 %), happiness (20.4–29.8 %) and positive affect (20.1 %). However, alexithymia failed to account for variance in either negative or positive well-being above and beyond the variance accounted for by the Big Five personality traits. These results are consistent with the position that alexithymia can be thought of as a constellation of extreme levels of normative personality traits.