In songbirds, both males and females can assess qualities of a singing male from features of its song. However, different features may trigger different responses in males assessing their rivals during male-male competition and in females searching for a mate. In some cases, the same feature could be under the conflicting pressure of intra- and intersexual selection. Chiffchaff males have simple songs consisting of several repeated syllables. The song length in chiffchaff does not reflect strength in aggressive interactions between males. But still, it could be important for females during the mate choice (e.g. as an indicator of a good territory). We found the song length to be negatively correlated with the frequency of songs, a trait often used by males to assess their rival’s fighting ability in many species. All males could potentially sing long songs to attract females unless there would be a mechanism preventing them to do so. We tested a prediction that low quality males (with high frequency of songs) singing long songs (probably attractive to females) are targeted with the increased aggressive behaviour of the other males. We studied responses of 48 chiffchaff males to four types of stimuli: long song / high frequency, long song / low frequency, short song / high frequency, short song / low frequency. In general, longer songs elicited stronger responses. Moreover, the response to long phrase / high frequency songs was the strongest according to our initial prediction, suggesting that weak males could be “punished” for displaying the trait they cannot afford.