The present study investigates some of the key elements of long-term happiness model. The main goal of this study was to examine the relationship between happiness-increasing strategies, personality traits and happiness level on the sample of Croatian students. A sample of 573 undergraduate students aged between 18 to 22 years, completed the List of HappinessIncreasing Strategies, Subjective Happiness Scale and the Croatian version of International Personality Item Pool -IPIP50. The results showed that females are generally happier than males. Comparing the frequency of use of happiness-increasing strategies between genders, females reported more often use of almost all happiness-increasing strategies (Social Affiliation, CognitiveBehavioural Interventions, Partying and Clubbing, Instrumental Goal Pursuit, Passive Leisure, Active Leisure and Religion), whereas males reported more often use of Sport and Hobby. Results of hierarchical multiple regression analyses showed that gender, personality traits and strategies explain for 51.4% of the happiness variance. Gender explained about 3% of happiness variance, personality traits in the second step of variables explained for 41.1% of the happiness variance, and happinessincreasing strategies in the third step explained an additional 8% of the happiness variance. When we reversed the set of variables entered in the model, happiness-increasing strategies in the second step explained for 25% of the happiness variance and personality traits in the third step explained an additional 26% of the happiness variance. Regardless of what set of variables was entered in the second or third step, results showed the same significant variables in the final regression analysis: Extraversion, Emotional Stability, Party and Clubbing and Cognitive-Behavioural Interventions. The findings showed the importance of personal traits as well as happiness-increasing strategies in predicting happiness among Croatian students.