We present two studies that together provide preliminary evidence to challenge the view that the relationship between adult attachment and mindfulness is bi-directional (Study 1: repeated measures design and Study 2: a repeated measures study examining the efficacy of attachment security priming and a mindfulness induction). Adult attachment anxiety emerged as a significant predictor of some facets of mindfulness, over time, but the reverse was not true. Priming attachment security increased state mindfulness of mind to a greater degree than a mindfulness induction or control. These findings challenge previous research suggesting that the relationship between adult attachment and mindfulness is bi-directional, suggesting that attachment orientation plays a causal role in the development of mindfulness.