OBJECTIVES: The aim was to describe HRQoL before and after solid organ Tx and to compare those outcomes among different transplants. METHODS: A prospective study was carried out in 17 Spanish hospitals. The HRQoL (before, at 3 and 6 months after Tx) was obtained using the Short Form-36 (SF-36,with 6 dimensions and 2 summary scores: physical-PCS and mental-MCS). Sociodemographic and clinical data were also collected. Mean postoperative scores were compared with mean preoperative scores to determine the effect of Tx. RESULTS: Five hundred eight kidney (Kd), 389 liver (Lv), 79 heart (Ht) and 143 lung (Lg) pts and 173 Kd, 200 Lv, 57 Ht and 46 Lg pts who received a transplant were studied. Mean age at Tx was 51 years; 70% were males. Different types of transplants start at different levels of HRQoL: Lg and Ht start out the worst, Lv in the middle, and Kd recipients the best. Comparison the SF-36 before and 3 months after Tx showed significant improvement, except Bodily Pain (BP) for Kd, Ht and Lg transplants. Six months of Tx, the HRQoL was considerably improved with respect to 3 months. The variations of SF36 were different between organs at 6 months post-Tx: for Kd transplant physical functioning (PF) showed similar scores but mental functioning (MF) was a little worse than at 3 months, for Lv all except General Health (GH) showed significant improvement, for Ht and Lg transplant social and MF showed a significant improvement and PF was a little better. Compared with the general population, all these pts were much worse before transplant. The Lg transplant express the best HRQoL on MCS. CONCLUSIONS: After Tx, improvement was clear with MF being the same as the general population, but there was still a significant physical deficit.