I know what you're talking about, so you're not crazy — or maybe we both are. I believe it mostly has to do with the rhythm and specifically the isochrony. In addition, I think some of the consonants are similar between Portuguese and Russian. Here's an interesting article comparing Brazilian and European Portuguese phonology, which I read a few months ago, that may prove interesting.

You're not crazy at all! The phonetic is quite similar and actually there is some funny videos on internet where there are russians speaking but with portuguese subtitles and it totally makes sense lol

Yes! Absolutely. That was my initial impression when I first heard European Portuguese many years ago, and I still think that now. The dark 'L' and the 'zh' consonants, especially. I was amazed that a Latin language could sound so, well, un-Latin. The city where I live in the UK now has many visitors and residents from all over Europe, so there's constantly a foreign buzz of languages here. And what's interesting is that it's often hard to tell, from afar or if there's a noisy background, whether people are speaking European Portuguese or a Slavic language.

I know many people claiming that, including me. I speak both and have to say they have many sounds in common, indeed. Here's what I found out so far: 1. There are both types of Russian 'l' sound in Portuguese: normal (dark) l (л) as well as the soft one 'lh' (ль) 2. The 'r' sound is trileld in both 3. The 'sh'/ш sound is frequent in both and sounds harder than for example the English one. 4. There is a reduction of vowels - in Russian only to some extent though. 5. Russian sound ы exists in Portuguese in non-stressed e's like leitE, quE, etc. (a sound closest to English 'i' in (bid, sit, etc.) 6. One of sounds represented by 'e' (exatamEnte) in Portuguese is close to Russian 'e' /ye/ Let me know if you found anything else ;) Cheers!

Olá tripeira! Você deve saber o melhor a resposta à sua pergunta. Quando você ouvir o português soa como ouvir o russo ? Bem, eu não sou nem um russo ou português e essas duas línguas são realmente diferentes de ouvir para mim. P.S. Und ja! Es ist sehr schwer Deutsch zu lernen und sprechen.