Background/Objectives: Timely and appropriate outpatient care can prevent potentially avoidable hospitalizations (PAHs) for heart failure (HF). We analyzed the trends, determinants, and consequences of PAHs for HF in Switzerland over two decades.; Methods: Hospital discharge data of Switzerland from 1998 to 2018 were utilized. PAH was defined according to the Organization for Economic Cooperation and Development (OECD) criteria.; Results: Data from 206,000 PAHs for HF were included (49.1% women, 55.8% aged over 80). Admission rates for PAHs represented 54.5 per 10,000 admissions in 1999, and they increased to 117.6 per 10,000 admissions in 2018. Similarly, age-standardized admission rates were 107.8 per 100,000 inhabitants in 1999, and they increased to 220.7 per 100,000 inhabitants in 2018. Between 1999 and 2018, patients admitted with PAHs for HF became older (% of patients aged over 80: 60.4% in 2018 vs. 49.2% in 1999), presented more frequently with a Charlson index < 4 (65% vs. 35%), were admitted more frequently as an emergency (89.0% vs. 60.7%), by the patient's own initiative (31.5% vs. 13.9%), while ICU admission increased only slightly (8.6% vs. 7.6%) and length of stay decreased-median and (interquartile range) 8 (6-13) vs. 12 (8-18) days. In 2018, the costs related to PAHs for HF were estimated at over CHF 170 million, and the corresponding number of occupied beds at 407 per year; Conclusions: In Switzerland, the number of PAHs for HF has increased steadily. The medical and financial burden due to PAH for HF could still be reduced with timely and appropriate outpatient care.