Hypoalbuminemia is common in acute heart failure (HF) patients and has been associated with increased hospital mortality and long-term mortality. Undernutrition is a factor causing hypoalbuminemia. The PICNIC study results show that a nutritional intervention in undernourished acute HF patients reduces the risks of all-cause death and of readmission for HF. We aimed to investigate whether the efficacy of a nutritional intervention is consistent among the subgroups of patients with and without hypoalbuminemia. In PICNIC study, a total of 120 malnourished hospitalized patients due to acute HF were randomized to conventional HF treatment or conventional HF treatment combined with an individualized nutritional intervention. The primary endpoint was a composite of all-cause death or readmission for worsening of HF, with a maximum follow-up of 12 months. In this post-hoc sub-analysis we assessed the interaction of the effects of a nutritional intervention among patients with and without hypoalbuminemia. Analysis was by intention to treat. 59 (49,2%) patients demonstrated hypoalbuminemia and 61 (50,8%) had normalbuminemia. At 12 months, the number of events for the primary endpoint in the intervention group compared with the control group was consistent among patients with hypoalbuminemia (28.6% intervention vs 61.3% control, HR 0,35, 95% CI 0,15–0,81) and those without (25.8% intervention vs 60% control, HR 0,35, 95% CI 0,15–0,79; interaction p = 0,86). There was no evidence that the relative efficacy of a nutritional intervention in undernourished acute HF patients was different between patients with normalbuminemia and those with hypoalbuminemia.